The public has for long time complained about the performance of customs and border control department due to its numerous complex procedures for clearance of goods imported to the country. This study examines the effectiveness of the computerized system on the performance of Customs and border control department of Kenya Revenue Authority. The research design used for this study was descriptive survey. The target population was 120. The sample chosen comprised staff working in various tax collection stations. The sample size comprised of 120 respondents selected using stratified random sampling. The main instrument of collecting primary data was questionnaire. Data was analyzed mainly by use of descriptive and inferential statistics. Descriptive statistics included mode, mean, median, standard deviation. Inferential statistical techniques like correlation and regression coefficients were used to draw relationships between the independent variables and the dependent variable. The study revealed that computerized systems have contributed positively to the performance of customs department.  Independent variables cargo security and tax clearance time had a positive significant impact on the performance. Revenue collection and tax administration had an insignificant impact hence there may be other many factors which affect revenue collection other than computerized systems. Based on research findings, the study recommends the need for Kenya Revenue Authority to recheck the need to enhance reforms and enhance systems validations and integrity so as to enhance customs performance. Systems enhancement based on risks management will be a key game changer in this era of digitization