Objectives The aim of the present study was to quantify the baseline variation in health-related quality of life (HRQOL) between individuals with Parkinson’s disease (PD) referred to a comprehensive care program and those attending standard neurological services. Methods Participants included individuals with PD receiving conventional care from neurologists in private practice and individuals referred to a comprehensive inter-professional team hospital out-patient service. The Parkinson’s Disease Questionnaire-39 (PDQ-39) and the EuroQoL (EQ-5D-3L) were used to quantify HRQOL. Results Participants referred to an inter-professional service were more likely to have poorer indices on PD-specific measures but not for generic HRQOL compared with individuals receiving standard neurological services. After adjusting for age, gender, disease severity and duration, people referred to a comprehensive care program were more likely to have a higher score for the PDQ-39 summary index (PDQ-39 SI; mean ± s.d. 27.2 ± 11.0; 95% confidence interval (CI) 25.5, 28.9) compared with individuals receiving standard neurological services (PDQ-39 SI mean 0.2 ± 12.8; 95% CI 18.0, 22.4). Conclusions Compared with those attending standard neurological out-patient clinics, individuals referred to an inter-professional PD program are more likely to have advanced disease and poorer HRQOL. This observation has implications for the way in which people with PD are recruited for future clinical trials, because uneven recruitment from different sources may be a potential source of bias. What is known about the topic? Given that PD is associated with a complex array of motor and non-motor symptoms, an inter-professional team approach to service provision is argued to be optimal for individuals living with this debilitating condition. What does this paper add? This paper has shown that individuals referred to an inter-professional service are more likely to have advanced disease and complex care needs. Compared with those referred to neurologist private clinics, those referred to an inter-professional clinic had less functional independence and lower PD-specific HRQOL when first assessed, even after controlling for disease severity. What are the implications for practitioners? When recruiting for future trials to examine the efficacy of multidisciplinary care programs in people with PD, it is important to take into account whether these individuals have been referred to an inter-professional service. There may be a potential source of bias if participants were recruited predominantly from such services.