This study sought to establish the relationship between internal controls and organisational performance of Medical and Molecular Laboratories Limited. The objectives of the study were to investigate the relationship between control environment, monitoring and control activities with organisational performance of Medical and Molecular Laboratories Limited. The study adopted a case study design to collect date from a sample of 40 using a questionnaire survey, interview and documentary review. Quantitative data was analysed using descriptive statistics, correlation and regression analysis. Qualitative data was analysed by thematic analysis. The results of the study suggested that there was a positive significant relationship between control environment and organizational performance (r = 0.824, p < 0.000). The critical value was significant at below 0.01 level indicating the acceptance of the research hypotheses that there was a positive significant relationship between control environment and organizational performance. The study found out that there was a significant positive relationship between control environment, monitoring and control activities with organisational performance. It was thus concluded that control environment, monitoring and control activities with organisational performance. Therefore, it was recommended that public organisations, NGOs/ private organisations and government agencies should establish a control environment, monitoring system and control activities that enhance organisational performance.