This study examines financial management practices among SMEs in Ghana, focusing on challenges, gender disparities, and impacts on sustainability. Using a cross-sectional survey of 242 Accra-based SMEs and OLS regression, we find that inventory/cost control (β = 1.737, p < 0.001) and financial advisory engagement (β = 0.836, p < 0.001) are key drivers of sustainability, while financial illiteracy negatively affects performance (β = −0.485, p = 0.049). Female entrepreneurs (80.58% of the sample) face disproportionate barriers, including poor record-keeping (12.40% vs males 2.89%) and limited access to finance. The study highlights the need for gender-sensitive literacy programs, FinTech adoption, and policy reforms to strengthen SME resilience. Theoretical contributions include applying the Resource-Based View and Pecking Order Theory to contextualize financial management in emerging economies. Limitations include sectoral bias (49.18% service firms) and geographic focus on Accra. Recommendations emphasize integrated solutions combining foundational practices (e.g., budgeting) with strategic interventions (e.g., cost control).