||Maize is a staple food for most households in Kenya and is grown in almost all agroecological zones. The yield of maize has not kept up with the rate of population growth, leading to serious food insecurity. A major reason seems to be the low uptake of new maize production technologies. Therefore, this study analyzes the attributes farmers consider in choosing their varieties, the use of local and improved varieties in different areas and by different groups, and the constraints farmers face in maize production, in particular pests and diseases. This research was executed in the moist mid-altitude zone in Western Kenya, as part of a nation wide study. The study involved literature review and Participatory Rural Appraisals (PRAs), entailing focused group discussions with male and female farmers as well as key informants. In total, 143 villagers (of which 60 women) participated in 8 group discussions in five villages, sampled from three districts. The districts were selected purposely to represent diverse ecological and socio-economic environments: Busia District (for the striga prone area), Butere-Mumias (for the sugarcane and maize zone) and Homa Bay (for the striga and drought prone area). In each district, the villages were selected using multi-stage random sampling. The moist mid-altitude zone covers a belt around Lake Victoria, from 1110 meter at the shore to about 1500 meter high. Rainfall increases with altitude and averages between 700 and 1800 mm annually, in a bimodal pattern. Mean annual temperature is 22.1 °C, with an average minimum temperature of 13°C and an average maximum of 30 0c. Soils are mainly clay-loam and sandy-loam and not fertile, since there is very little volcanic or other young parent materials. The PRA results show that farmers have diverse selection critera for maize varieties and use them in a diverse combinations. The top three criteria are high yield, early maturity, and tolerance to Striga. Other important criteria are, in order of importance, the low cost of acquiring the seed, grain characteristics, low external input demand and resistance to field and storage pests. Criteria differ among sites and between groups, reflecting in a different use of varieties between sites and between groups. Farmers grow a wide range of varieties. In total, twenty different varieties were identified in the zone, of which 8 are local. In each district, farmers grow 9 or 10 varieties, of which 3-4 local. Local varieties are overall more popular than improved varieties. Only one, Shipindi, is grown in two districts. Three local varieties are grown by a majority of farmers in their district, but are not found in the other districts: Ke-Buganda in Busia, Samaria in ButereMumias, and Nyamula in Homa Bay. Shipindi and Nyuamula are popular yellow varieties, although their price is generally lower than for white maize varieties. The heterogeneity of the zone is also reflected in the range of improved varieties. They include late maturing hybrids such as H622 (grown by 28% of farmers present at the meetings) and H614 (21 %), the OPV Katumani (second in popularity with 26%), and medium length hybrids such as Pioneer 3253, H513 and H511. There is also a clear gender distinction: within a locality, more women usually grow the local varieities, and more men hybrids. The most important constraints to maize production, as reported by the farmers, are low soil fertility, cash or credit availability to purchase inputs, and poor extension service. The farmers explained that the cash constraint is a major problem, and its alleviation would lead to alleviation of many other constraints. The next group of constraints is the lack of farm implements and the related lack of labor. The first pest, striga, is mentioned next. Other stresses that are frequently mentioned include, unreliable rainfall, pests and diseases. Quality of seed are also frequently mentioned, although not the cost of seed. Diseases do not usually rank high on the farmers' perceived constraints list. As a result of cash and other constraints, farmers recycle varieties for long period of time, especially the local varieties but also the hybrids. They apply little or no fertilizers and no pesticides in maize fields. Striga, a parasitic weed typical for the zone, was generally perceived as the most important pest, followed by stem borers and weevils, a major storage insect pest. In Busia, stem borers were rankend first, and in Butere-Mumias, weevils were considered more important than stem borers. Losses due to stem borers were estimated at 20-30%. Farmers would be interested in buying varieties resistant to stem borers, but their price should not be more than 25% higher than that of existing varieties. Farmers are clearly interested in new varieties, and will adopt them as the recently introduced Pioneer 3253 shows. However, new varieties and crop management practices need to take into account not only farmers' preferences, but also their conditions. These conditions include erratic rainfall, low soil fertility and low input use, exacerbated by lack of credit and available labor, all within a framework of unclear agricultural policies. There are clearly opportunities for a wide range of varieties in the zone, and breeders should focus on hardy varieties that are not dependent on high input use, and with resistance to striga, stem borers and weevils. The government can help improve the conditions for maize producers by setting and implementing clear policies. Policies are needed to encourage new companies to develop new varieties, while at the same time setting high quality standards and providing the regulatory agencies with the means for quality control. The government needs to provide the means for agricultural extension, and set policies to promote the provision of extension and credit by NGOs and the private sector. Seed producers and distributors need to operate efficiently so that the price of new varieties does not increase by more than 25%, the maximum increase farmers are willing to accept.