In adult education, understanding the dynamics of motivation among incarcerated individuals to attend English as a Foreign Language (EFL) classes is crucial for effective educational programming, successful rehabilitation, and recidivism reduction efforts. The present study, focusing on Greek prisons, investigates two key aspects: a) the influence of sociodemographic factors (marital status, age, gender, and occupation previous to sentence) on inmates' motivation to attend EFL classes and b) the relative prevalence of intrinsic and extrinsic motivational factors driving inmates to attend EFL classes. Grounded in theories of foreign language learning motivation, the study employed quantitative methods with a large sample of 400 adult inmates enrolled in English classes at Second Chance Schools across all Greek prisons. The findings reveal that marital status, age, gender, and previous occupation are factors that significantly impact inmates' motivation to attend EFL classes, with female inmates demonstrating higher motivation than their male counterparts. Notably, the study highlights the predominance of extrinsic motivation among inmates, with the desire to make their families proud being the most highly rated motivational driver.