Few studies have examined the concepts of workstyle and overcommitment in relation to the occurrence of neck and upper limb symptoms. The aim of this study was to examine whether a high-risk workstyle is a mediator in the relation of work-related exposure (job demands and computer work) and overcommitment to neck and upper limb symptoms. The study participants comprised 3,855 office workers of a European institute. The Sobel test was applied to test the intermediate effects of 4 workstyle dimensions and of the total workstyle score. The results show that most mediated effects were statistically significant, meaning that the workstyle dimensions acted as a mediator in the relation between work-related exposure and symptoms as well as in the relation between overcommitment and symptoms. Given the results with the total workstyle score, 34% of the effect of prolonged computer work, 64% of the effect of job demands, and 84% of the effect of overcommitment was mediated by workstyle. However, due to possible bias in the assessment of workstyle factor and the cross-sectional design of the study, the conclusions should be drawn with care.