This study examined the influence of public sector accounting practices on service delivery efficiency in Nigerian public sector institutions. Specifically, the study focused on budgetary control and internal audit practices as independent variables, and timeliness and quality of service delivery as dependent variables. The study adopted a descriptive survey research design, targeting accountants, auditors, finance officers, and service managers across selected federal, state, and local government institutions. A total of 250 respondents were sampled using stratified random sampling, and data were collected via a structured questionnaire. Descriptive statistics, correlation, and multiple regression analysis were used to analyse the data. The findings revealed that budgetary control has a significant positive effect on the timeliness of service delivery, while internal audit practices significantly enhance the quality of public services. Collectively, budgetary control and internal audit practices explained 67.2% of the variation in service delivery efficiency (R² = 0.672), and the regression model was statistically significant (F = 254.36, p < 0.001). The study concludes that robust accounting practices are critical for improving the efficiency, accountability, and effectiveness of public service delivery in Nigeria. Based on these findings, the study recommends strengthening budgetary control mechanisms, enhancing internal audit functions, adopting digital accounting systems, and enforcing policy reforms to improve transparency, reduce delays, and enhance the quality of services.