The need to effectively integrate gender in agriculture is a topical issue in research and policy debates. Previous studies have shown that women in Sub-Saharan Africa (SSA) face challenges in accessing productive resources such as land, and this reduces their productivity compared to men. Most of these studies, however, have analyzed male-headed versus female-headed households, and this approach fails to take into account the women who are in male-headed households, for example. Moreover, the combined effect of gendered decision-making and access to institutional support services on agricultural productivity and efficiency has not received adequate focus in empirical work. The main objective of this study was to assess the effect of intra-household decision-making and access to institutional support services (group membership, credit, extension, agricultural training forums) on maize production efficiency in Kenya. Using primary data collected from Bungoma and Meru counties, a multivariate probit model was applied to analyze factors affecting men’s and women’s participation in decision-making, while stochastic frontier production functions were used to estimate technical efficiency. Findings indicate that men and women do not have equal roles in household decision-making and access to institutional support services. Women had higher group membership while men had higher education levels, access to agricultural training forums and were found to be more likely to contribute to decisions on input and labour use. Extension, mobile phone use and credit had a positive effect on efficiency. Based on these results, the study recommends implementation of gender-based interventions such as agricultural training forums for women, as well as providing incentives that encourage men to join and contribute productively to agricultural development groups. This will ensure fairness in access to resources and improved efficiency.