The study aims to analyse the effect of claims management on firm performance of insurance companies through marketing factors. The data was collected from 776 of management, senior and junior (frontline) staff of selected Insurance companies in Lagos State using a questionnaire as a data collection tool. This research uses a quantitative approach with a survey method. Respondents were selected from the the 20 registered insurance companies across composite, general and life Insurance businesses in Lagos State through a stratified ransom sampling technique. The collected data were analysed using hierarchical regression analysis (HRA) to test hypothesis and evaluates the regression model specified. The collected data were analysed using hierarchical regression analysis (HRA) to test hypothesis and evaluates the regression model specified. The findings indicates that marketing factors significantly moderated the effect of claims management practices on firm performance of selected Insurance Companies (β = -0.009, R2∆ = 0.002; F∆ = 17.928, p < 0.05). The study concludes that marketing factors moderated the effect of claims management practices on firm performance of selected Insurance Companies in Lagos State. The study therefore recommends that the management of selected insurance companies in Lagos State focus on creating a positive marketing factor that bolsters claims management practices to achieve a sustainable performance in the industry. This may involve developing marketing policies and training that encourage employee involvement, job satisfaction, and a positive working environment.