This study explored the mediating effect of customer satisfaction on factors influencing post-purchase behaviour among smartphone users in Tanzanian universities. The study was guided by the Expectation Confirmation Theory. A cross-sectional design and convenience sampling were used to select 700 participants, and data were collected through structured questionnaires, and analysed using SEM-PLS in SmartPLS 4.0. Findings showed that customer satisfaction significantly mediates the impact of product performance (β = 0.084; T = 4.918; p = 0.000), after-sales service (β = 0.044; T = 3.490; p = 0.000), and brand equity (β = 0.194; T = 8.024; p = 0.000) on post-purchase behaviour. The model exhibited strong explanatory power (R²: CS = 0.495; PPB = 0.557), good predictive relevance (Q²: CS = 0.487; PPB = 0.472), and acceptable fit (SRMR = 0.058). The study concludes that enhancing customer satisfaction through quality products, strong branding, and effective after-sales service fosters loyalty and repeat purchases. It recommends that firms prioritize these factors to strengthen customer retention