Maize (Zea mays L.) plays a critical role in smallholder food security in Ethiopia. Its production is rapidly increasing to the Highlands of Ethiopia where it has been a minor crop in the past. This study aimed to assess the magnitude and production systems of Highland maize, farmers’ production constraints, and their implications for the adoption of new maize cultivars in two zones of the Oromia Regional State representing the Highland sub-humid agro-ecology of Ethiopia. A participatory rural appraisal (PRA) was conducted with eight peasant associations involving 160 experienced maize farmers from four districts during 2012. Primary data were collected through Focused Group Discussions (FGDs) and Semi-structured Interviews (SSI). Farmers’ maize cultivar preferences showed that few adopted Highland cultivars are available. Instead a two-decade old cultivar, ‘BH660’, originally released for the mid-altitude agro-ecology, has been widely adopted in most Highland areas. As regards cultivars’ trait preferences, non-significant variation (P > 0.05) was observed among farmers between the two study zones. Farmers (both men and women) in the study areas unanimously considered grain yield as the most important trait for maize cultivar selection. Major production constraints were also identified and listed by farmers, of which limited access to inputs (improved maize seeds and inorganic fertilizers), and late on-set and inadequate rainfall were the primary constraints across the study areas.