OBJECTIVES: To understand the patterns of health care utilization in employees with multimorbidity (more than one chronic condition in one individual), we: (1) characterized diseases in terms of comorbidity status (alone and coexisting with other chronic diseases); and (2) determined the associations between multimorbidity and disease-specific healthcare utilization (HSU) among these employees. METHODS: Data were derived from the cross-sectional 2011-12 Australian National Health Survey (NHS) which included the self-reported data from 10363 employees aged 15 years and over. HSU in the 12-months prior to the face-to-face NHS interview, was collected for each current and chronic condition: asthma, cancer, cardiovascular disease (CVD), arthritis, osteoporosis, diabetes, kidney disease, and mental/behavior disorder. Descriptive, logistic and Poisson regression analyses were used, and the models were adjusted for the complex sampling design used by the NHS.  RESULTS: Results showed employees with multimorbidity have more disease-specific HSU for CVD and arthritis, separately, after controlling for age, sex, BMI, and educational attainment. Multimorbid employees with arthritis had higher adjusted rates of arthritis-specific visits with general practitioners (RR = 1.7, 95% CI = 1.1-2.2, P<0.001) than those with arthritis only. Multimorbid employees who had CVD had higher adjusted rates of CVD-specific visits with specialists (RR = 1.6, 95% CI = 1.1-2.5, P<0.05), and 2.5 times (OR = 2.5, 95% CI = 1.5-4.0, P<0.001) CVD-specific visits with other health professionals than those with CVD only.  CONCLUSIONS: Our study is the first to examine the associations between multimorbidity and disease-specific HSU in a nationally representative working population. HSU varies depending on which diseases are coexist. This has implications for health care planning for the growing number of employees managing work and chronic conditions.