An aggressive research and validation program launched in 1984 in Azuero, Panama, yielded a recommendation advocating zero tillage for maize production. Ten years later, maize farmers in Azuero used three land preparation methods: conventional tillage, zero tillage, and minimum tillage (an adaptation of the zero tillage technology). This study aimed to quantify the adoption of zero and minimum tillage for maize in Azuero; identify factors influencing adoption of the different land preparation practices; and analyze the implications of the findings for future maize research and extension. Between 1985 and 1994, farmers in Region I of Azuero changed from conventional tillage to zero (33%) and minimum tillage (43%). In Regions II and III, most farmers still practiced conventional tillage in 1994, although 34% had switched to minimum tillage. Across regions, adoption of conservation tillage was motivated by potential cost savings rather than longer term considerations such as reduced soil erosion. The factors that limit adoption of conservation tillage vary by region. In Region I, adoption of conservation tillage is limited by land rental rather than ownership and by lack of conservation tillage planting equipment. In Regions II and III, lack of information about conservation tillage technology limits the probability of adoption. Future research should examine soil compaction, a key variable for understanding differences between the adoption of minimum and zero tillage. Another area that merits further research is the link between weeds and conservation tillage: several farmers reported using the technology to obtain better weed control. The long-term effects of conservation tillage should also be assessed. Extension in Regions II and III should seek to accelerate adoption of conservation tillage, particularly zero tillage. In Region I, extension should steer the change process from minimum to zero tillage.