Improved maize seed varieties are bred with characteristics such as drought and disease tolerance which may not capture farmers’ preference. It is therefore, imperative to consider attributes that are preferred by farmers in developing maize seed varieties. This research was conducted to determine attributes that are most preferred by smallholder maize farmers in Tanzania. Specifically, the study aimed to (i) characterize smallholder farmers’ preferences for improved maize seed varieties depending on their socio-economic characteristics, (ii) assess the heterogeneity of farmers’ preferences for improved maize seed varieties and (iii) determine factors that influence farmers’ choice of the most preferred improved maize seed varieties. Descriptive statistics and binary logistic regression were used for data analysis. The study findings revealed that majority (74.7%) of the households were male-headed and (83%) were married. About 90 percent of the farmers had no access to extension services that is supposed to play an important role in agricultural information dissemination. The most preferred improved maize varieties in all zones were PAN6549, SC 627, SC 713, STAHA, KILIMA and DK 8371due to higher production potential. A Logit model showed that agro-ecological zones, farm size, household size and yield positively influenced the likelihood of farmers’ choice of improved maize seed varieties. Based on these findings, it is recommended that researchers and suppliers of seed should consider the attributes of farmers’ preference in the production of improved maize seeds and put more emphasis on facilitating the delivery of agricultural extension services for more effective uptake of agricultural technologies.