Abstract: This study aimed to examine the internal financial factors affecting the performance of six manufacturing firms listed on the Dar es Salaam Stock Exchange (DSE) in Tanzania between 2010 and 2023. Specifically, it investigated the impact of internal financial factors comprising of liquidity, efficiency and leverage on firm performance, measured by Return on Assets (ROA) and Return on Equity (ROE). This study employed a longitudinal research design using secondary data from audited annual financial reports of the six firms. The focus was on six publicly listed Tanzanian manufacturing firms with over 14 years, integrating internal financial factors in a longitudinal framework and providing updated empirical evidence. Descriptive statistics, correlation analysis, and diagnostic tests were conducted, followed by regression analysis using the Auto Regressive Distributed Lag (ARDL) model to determine relationships between independent variable and firm performance. Stationarity of the data was verified through the Augmented Dickey-Fuller (ADF) test. Results indicate that internal financial factors significantly influence firm performance. Liquidity was positively correlated with ROA (0.642) and ROE (0.713), with regression showing a 1% increase in liquidity improving performance by 2.62% (p = 0.0084). Efficiency had the strongest impact, where a 1% increase improved performance by 44.07% (p = 0.0022). Leverage negatively affected performance, reducing profitability by 4.81% per 1% increase (p = 0.0245). Overall, the ARDL model explained 74.5% of variations in firm performance (R² = 0.745). Managers should prioritize liquidity and operational efficiency prudently. Policymakers can support sector performance through policies and regulatory frameworks that encourage efficiency. Enhanced performance of manufacturing firms can contribute to industrial growth, employment creation, and economic development, improving social stability and livelihoods in Tanzania. 

Keywords: Firm Performance, Liquidity, Efficiency, Leverage, Dar es Salaam Stock Exchange