Purpose To study associations between the level of self-reported work motivation and employment outcomes in people with severe mental illness (SMI) enrolled in a vocational rehabilitation program. Methods Data of 151 study participants, collected from a randomised controlled trial with a 30-month follow-up period, were used for a secondary data analysis. Multiple logistic regression, linear regression and cox regression analyses were performed to analyse the association between the level of work motivation at baseline and job obtainment, duration of job, and time until job obtainment during the 30-month follow-up period. Results No statistically significant associations were found between the level of work motivation and job obtainment (OR 1.83, 95% CI 0.55–6.06, p = 0.32), job duration (B = − 0.74, 95% CI − 2.37 to 0.89, p = 0.37, R-squared = 0.03), or time until job obtainment (HR = 1.53, 95% CI 0.64–3.68, p = 0.34). Conclusions The results of this study show no statistically significant associations between the level of work motivation and employment outcomes in people with SMI enrolled in a vocational rehabilitation program. These associations may be underestimated due to range restriction of the work motivation’s level. Further research is recommended to increase knowledge on the associations between work motivation and employment outcomes, as it could be relevant for further understanding success in vocational rehabilitation.