Objective: This article examined whether occupational factors predicted 4-year change in body mass index (BMI) in a sample of full-time Australian employees. Methods: Data from 1670 full-time Australian employees were collected through the Longitudinal Study of Australian Children. Multinomial logistic regression was used to examine whether several occupational factors at baseline predicted changes in BMI at 4-year follow up; several health and demographic covariates were controlled. Results: Inflexible working hours (odds ratio = 1.54, 95% confidence interval [1.14 to 2.09]) and weekend work (odds ratio = 1.33, 95% confidence interval [1.04 to 1.68]) significantly predicted increased BMI. Conclusions: This article demonstrates that certain occupational factors (ie, inflexible work hours and weekend work) significantly predicted increased BMI. Targeting these factors may play a role in combating obesity and related health problems among employees.