Responding to enormous enrollment increases, Mexican universities were forced to hire faculty without a Licenciatura degree (corresponds to a United States bachelors degree) and so initiated faculty development activities (FDA) to enhance the performance of underqualified and new teachers. This study assessed the impact of one of these FDAs at the Autonomous University of Aguascalientes, a public university established in 1973. A theoretical model was constructed, and a sample of 302 faculty members was selected. Quantitative information was collected and field work, i.e., observing and interviewing selected cases, was carried out. Multiple regression analysis of data, supplemented by qualitative analysis, offered a basis for the conclusions, and controlled the influence of the other variables included in the model. Results suggested that FDAs were useful for teachers; that though student ratings favored teachers who did not participate in FDAs, this may be explained by the association of inferior ratings with inexperience or insecurity; and that younger, female, part-time teachers did benefit from FDAs though it is not clear whether that improvement is due to FDAs or the effect of maturation and increased security. In addition, the study found that FDAs should be tailored to teachers with different needs. Sixteen references are offered. (JB)