This study examines the influence of monitoring and evaluation (M&E) practices on irrigation project performance in Tharaka-Nithi County, Kenya, focusing on baseline surveys, stakeholder participation, budgetary allocation, and capacity building. Employing a descriptive and explanatory research design, data were collected from 126 respondents across three major irrigation schemes using structured questionnaires. Multiple regression analysis revealed that these M&E practices collectively account for 24.5% of the variance in project performance (R² = 0.245, p < 0.001). Budgetary allocation emerged as the most significant predictor (? = 0.807, p < 0.001), demonstrating a strong positive correlation with project success. Stakeholder participation showed marginal significance (? = 0.135, p = 0.053), while baseline surveys exhibited minimal impact. Capacity building presented a complex relationship requiring further investigation, showing a positive bivariate correlation but a negative regression coefficient. The findings emphasise the critical importance of adequate M&E funding and integrated frameworks for achieving sustainable irrigation outcomes and addressing Kenya\'s persistent food security challenges in semi-arid regions.