Worldwide, insurance companies play a vital role in contributing to the efficient resources allocation through risk management in most sectors of the economy. Insurance has existed since civilizations initially presenting itself in the form of mutual help. One of the fundamental services offered by the insurance company is to provide its customers with claims settlement. The general objective of this study was to assess the effects of claims management on financial performance of insurance companies. The study used a case study research design whereby descriptive approaches were applied to collect quantitative and qualitative data using questionnaire and interview guide. The researcher targeted 93 permanent employees, 10 registered agents, 13 contracted brokers, and 205 claimants in Kigali City. Findings on claims management processes in SONARWA General Insurance which are claims planning, claims control, claims monitoring and evaluation show that they are frequently undertaken as it is indicated by the weighted means ranging between 1.00 ≤ mean score ≤ 1.50. The financial ratios indicate that there is a constant stagnation of financial performance as indicated by 3.6% of ROI in 2014 and the same percentage in 2018. Although there has been a sharp increase in 2016 followed by a sharp decrease in 2017 on ROE and ROA, the graph indicates that these have been approaching stagnation over other years. However, the correlation is not statistically significant. It was observed that claims planning and claims M & E has a significant positive correlation with ROI indicated by a Pearson Correlation value of (0.481** and ρ-value of 0.000; 0.329* and a ρ-value of 0.015: ρ ≤ 0.05). Finally, the study established that there is a positive correlation between claims planning, claims control and claims M & E on ROE. Moreover, the correlation between claims M & E and ROE is statistically significant as indicated by Pearson correlation value of 0.276* and ρ-value of 0.