Background: A comprehensive understanding of factors associated with multiple sclerosis (MS)-related work productivity loss will inform targeted interventions. We have previously shown the strong impact of symptom severity on MS-related work productivity loss. However, the effect of work difficulties, work self-efficacy and work psychological safety is yet to be well evaluated in this context. Objectives: This study evaluates the association between work difficulties, work self-efficacy and work psychological safety, and MS-related presenteeism, absenteeism and total work productivity loss. Methods: We analysed data from employed participants of the Australian MS Longitudinal Study (AMSLS) who took part in both the 2015 Medication and Disease Course survey, and 2015 Employment survey ( n = 744). Data were analysed using Cragg Hurdle regression models. Results: We found that low workplace self-esteem, interpersonal difficulties at work and work self-efficacy were associated with total work productivity loss. In a multivariable model, a 10-unit decrease in workplace self-esteem, increase in interpersonal difficulties at work and 5-unit increase in work self-efficacy were independently associated with a 3.75% increase, 2.89% increase and 3.36% reduction in total work productivity loss, respectively. When separating total work productivity loss in presenteeism and absenteeism, stronger effects were seen for presenteeism than absenteeism. Surprisingly, work psychological safety was not associated with MS-related work productivity loss. Conclusion: Work psychosocial well-being such as self-confidence at work, work self-efficacy and interpersonal difficulties at work are crucial factors governing work productivity in people with MS (PwMS). Multidisciplinary support team assistance of PwMS in symptom self-care, skills around effective communication about MS in the workplace, the psychological impact of work and the modification of work demands may positively influence the employment outcomes.