Despite the accumulating evidence regarding the prevalence and effects of workplace bullying and harassment (WBH), extensive studies focusing on the Japanese construction industry remain scarce. Thus, this study aimed to assess the prevalence of WBH, examine the cross-sectional associations of WBH with subjective health and work attractiveness, and investigate the moderating effects of project duration and the number of technical personnel on these relationships among a sample of engineers working at construction sites. Logistic regression analyses were conducted using 5781 responses to the ‘Questionnaire survey for the reduction of working hours, and fact-finding survey on the attitudes toward life (2021),’ to estimate the corresponding odds ratios and 95% confidence intervals. The results indicated an overall prevalence rate of 19.5%. Negative associations of WBH with subjective health and work attractiveness were also demonstrated after adjusting for demographic and occupational characteristics. Additionally, a shorter project duration and a larger number of technical personnel ameliorated the negative association of WBH with work attractiveness. When stratified by gender, similar results were found only among males. These findings suggest that assigning high-risk groups of engineers to projects with shorter durations or a larger number of technical personnel could mitigate the detrimental effects of WBH.