Background We assessed the community-level spatiotemporal connexions between hospitalisations for common opioid comorbidities (HIV, hepatitis C (HCV) and mental disorders) and opioid-related hospitalisations in the current and previous year. Methods We used Bayesian hierarchical spatiotemporal Poisson regression with conditionally autoregressive spatial effects to assess counts of HCV-related, HIV-related and mental disorder–related hospitalisations at the ZIP code level from 2004 to 2014 in Pennsylvania. Models included rates of current-year and previous-year opioid-related hospitalisations as well as covariates measuring demographic and environmental characteristics. Results After adjusting for measures of demographic and environmental characteristics, current-year and previous-year opioid-related hospitalisations were associated with higher risk of HCV, HIV and mental disorders. The relative risks and 95% credible intervals for previous-year opioid-related hospitalisations were 1.092 (1.078 to 1.106) for HCV, 1.098 (1.068 to 1.126) for HIV and 1.020 (1.013 to 1.027) for mental disorders. Conclusion Previous-year opioid-related hospitalisations are connected to common comorbid conditions such as HCV, HIV and mental disorders, illustrating some of the broader health-related impacts of the opioid epidemic. Public health interventions focused on the opioid epidemic must consider individual community needs and comorbid diagnoses.