We have assessed the impact of three seed-based intervention programs on crop diversity levels of pigeon pea (Cajanus cajun) in the semi-arid districts of Kitui and Makueni in eastern Kenya. We adopted four-cell analysis along with focus-group discussions to determine the cultivar diversity of pigeon pea. Often intercropped with maize (Zea mays L.), pigeon pea is widely adapted to drought conditions and has multiple uses — as green vegetable and as food grain. It was evident that the existing local crop diversity also had an impact on local foods in the communities. The food preferences of the local population underlined the value attached to maize, pigeonpea, beans, and cowpea. All three seed interventions, producer-marketing groups (PMGs), community-based seed production programs (CBSP) and seed vouchers and fairs (SV&F) have had an impact on the overall crop diversity as well as on the pigeon pea crop diversity in the region. However, the cultivar diversity of pigeonpea was significantly higher in PMG sites than in CBSP and SV&F areas. Farmers located in PMG areas, had increased access to improved and quality planting materials of pigeonpea during normal and distress periods. The seed prices were more stable in the PMG sites than in the other intervention sites, due to proper marketing tie-ups for seeds and the grain. The results from our study further indicate that seed-based interventions, such as PMGs, are effective in providing improved seeds of dry-land crops like pigeon pea during normal and disaster periods. However, it was not clear if the improved varieties had displaced the existing local or land races of pigeon pea in the system, which requires a more rigorous study. This also calls for an effective and sustainable, seed-based initiative that provides quality seeds on time as well in improving the cultivar diversity during normal and distress periods in the semi-arid regions of eastern Kenya.