This report of the adoption of maize production technologies in Southern Tanzania forms part of a larger study to evaluate the impact of maize research and extension throughout Tanzania over the past 20 years. Using a structured questionnaire, researchers and extension officers interviewed farmers in June-November 1995. Maize is the major food and cash crop in the study area. Farmers have easily adopted improved maize technologies that required little cash (row planting, weeding), but only a few farmers had adopted the more costly technologies such as fertilizer, herbicide, and disease control measures. Additional efforts by research and extension are important for increasing the adoption of improved maize technologies. Research should give high priority to developing varieties that yield well, tolerate drought stress, and resist field pests. More research should be conducted on soil fertility and conservation practices, because the use chemical fertilizer is likely to remain low in the foreseeable future. Many respondents in the sample were unaware of improved maize technologies, especially the use of fertilizers, use of ox-drawn implements, herbicide use, and disease control measures. Farmers' low rate of contact with the extension service and agricultural research may be a constraint on the use of these technologies. Communication between farmers, research, and extension could be improved through on-farm trials and field days. Poor infrastructure and untimely delivery of inputs were also important constraints on the adoption of improved maize technologies in Southern Tanzania. Policy makers should support the promotion of an efficient affecting system (especially rural access roads) for outputs and inputs. Such a system would offer higher maize prices to farmers and reduce the cost of fertilizers. Also, studies on the economics of fertilizer use should be undertaken, especially now that input and output markets have been liberalized. Formal credit is not available to farmers, although providing credit to farmers becomes increasingly important with rising input prices. the formal credit system needs to address the credit problems faced by small-scale farmers, especially their lack of knowledge (information) of formal credit systems.