The insurance sector reforms in Nigeria sought to create a strong, diverse, and trustworthy industry that protects insured premiums, actively contributes to the country's economic progress, and participates in worldwide financial systems. Despite this development, insurance business operations and survival have not been impressive, and performance remains alarmingly poor. Therefore, this study investigates the effect of workers' compensation written premiums and workers' compensation claims paid of the chosen insurance companies' return on assets (ROA) in Nigeria. This study is a longitudinal research design. Secondary data obtained from the financial statement of five selected insurance firms in Nigeria over the year 2013 to 2022 were analysed with correlation analysis and panel regression estimation technique. The result of the study, based on Hausman verification, showed that workers' compensation written premium has a significant positive effect on RoA and that workers' compensation claims paid has a significant negative effect on RoA in Nigeria. Consequently, this investigation established that liability insurance is an important factor that may have been disturbing the performance of insurance firms in Nigeria, and must be treated with utmost care in the process of enhancing performance. Therefore, this study recommended among others that insurance firms need to increase the rate of client application towards workers' compensation insurance to realize increased levels of premium and income for performance-enhancing operations.