Adoption of climate-smart practices (CSP) and the effects on production efficiency of maize farmers in Northern Nigeria was carried out withprimary data, collected with the use of structured questionnaires and household interview method administered on educated and illiterate farmers, respectively. Descriptive and inferential statistics analysed the data and identified the constraints tothe adoption. Richardian net revenue technique estimated the costs and returns, while Multinomial logit statistics interpreted the probability ofCSP-adoption or non-adoption based on farmers'characteristics. Marginal factor productivity analysis determined the influence of CSP-adoption on the production efficiency, while Likert scale established severity of adoption constraints.Kano's 168 CSP adopters' and 110 non-adopters' mean incomes were ₦140,198 and₦54,622at ₦2 and ₦0.8 returns, respectively. Nasarawa's 107 CSP-adopters and 106 non-CSP incomes were ₦162,545 and ₦85,570 at ₦1.8 and ₦0.9returns, respectively. Kano and Nasarawa CSP-adopters'estimated Pseudo-R 2 were 51% and 50% at 52% and 51% significant Log likelihood ratios (LR),respectively. Access to credit, extension, educational level and income were significant and positively related to CSPadoptiondecisions at P≤0.5 and P≤0.1 in Kano and Nasarawa, respectively. The CSP-adopters were technically efficient and Z-test 2.61 and 2.83 at P≤0.1 for Kano and Nasarawa, respectively,at 35%coefficient of variation rendered the hypothesis of no significant difference between the mean incomes of both farmersto be rejected. High cost of inputs was the most severe constraint to CSP-adoption. Thus, maize farmers are advised to join cooperative societies to enjoy cheaper production costand increase production efficiency.