Scheduled and occasional overtime practices have been used frequently in the construction industry. Past research indicated that continuous scheduled overtime could have a negative effect on labor productivity. The impact of occasional overtime on productivity is generally expected to be less than the impact of scheduled overtime. However, few studies have evaluated the effects of occasional overtime on productivity, which is the main objective of this paper. Productivity data for 234 weeks were collected for quantitative analysis. The t test was performed initially to determine the statistical significance of the impact of occasional overtime. The assessment of productivity data samples revealed possible deviations from the normal distribution. The Wilcoxon rank sum test was implemented as an alternative to the t test. The results of quantitative analysis indicate that moderate levels of occasional overtime did not have a significant impact on productivity. Based on the findings in this study, the potential advantages of occasional overtime practices are discussed.