The study was to establish the effect of Examiners’ personality and effectiveness on conveyor belt system of marking in Uganda that looked at Namungoona High Secondary School as a case reference. The study was guided by a secondary objective of to examine the effect of Examiners’ attitudes on effectiveness of conveyor belt system of marking and to establish the effect of Examiners’ values on effectiveness of conveyor belt system of marking This research was based on a descriptive research design to describe the effect of Examiners’ personality on effectiveness of conveyor belt system of marking. The study used a research population of 260 and a sample size. The findings showed out that there exists a positive and significant relationship between Examiner’s attitudes and effectiveness of CBS of marking, which implied that positive Examiners attitudes increase on the effectiveness of CBS of marking and negative Examiner’s attitude reduces it, the findings revealed that there is a significant relationship between Examiner’s values and effectiveness of CBS of marking and this implied that good Examiner’s values significantly increases the effectiveness of CBS of marking, the findings proved a positive significant relationship between Examiners values and effectiveness of CBS of marking, the finding proved a positive significant relationship between Examiner’s beliefs and effectiveness of CBS of marking, this therefore implies that favorable. The researcher concluded that; positive examiners attitudes increase the effectiveness of CBS of marking and negative can reduce it, the researcher also concluded that; positive examiners attitudes increase the effectiveness of CBS of marking and negative examiners attitudes reduce it. The researcher also concluded that good examiners values significantly increase the effectiveness of CBS of marking, and lastly; the favorable examiners beliefs can improve on the effectiveness of CBS of marking and unfavorable examiners beliefs reduce it. The researcher recommended that; Institution should train the examiners about other marking systems or techniques, this will help them believe that using a CBS of marking is not the only best way of marking the examinations, Institution should always organize orientations specifically for new markers, Institution should always put rules and regulations governing the examiners arrival in the marking room