Objective: To estimate the prevalence of smoking in workers from hospitals within the Catalan Network for Smoke-free hospitals from 2009 to 2012 according to workers' sociodemographic characteristics and the type of hospital. Method: A meta-analysis was performed of prevalence surveys from representative samples of workers from 45 hospitals. The combined prevalence for all hospitals was calculated using a regression model with a random effects model weighted by sample size. Results: The overall prevalence of smoking was 28.1% (95%CI: 26.1 to 30.0%) with a maximum and minimum of 40.3% and 19.1%, respectively. The health professionals with the lowest prevalence of smoking were physicians (16.4%; 95%CI: 12.9 to 19.9) and nurses (25.4%; 95%CI 21.6 to 29.2). Conclusion: The prevalence of smoking in hospital health workers was lower than in the general population of working age. Physicians were the group with the lowest smoking prevalence. Smoking cessation should be promoted among other professional groups.