The occupants of hospitals like other buildings have widely differing thermal comfort requirements due to their different levels of clothing and metabolism. The study indicated three main groups of occupants in Iranian hospitals as: patients that are able to be covered, patients that are not able to be covered regarding their medical conditions, and staff. This study investigated the thermal comfort calculated to have been achieved for different occupants in Iranian hospitals. The ‘thermal comfort achieved’ findings have been derived from basic monitoring of those parameters which affect thermal comfort in 14 rooms in 4 separate Iranian hospitals. The thermal comfort results calculated for each room are compared with recommended Iranian and international standards for acceptable thermal comfort. The findings from this study showed a wide range of thermal comfort conditions were achieved in Iranian hospitals, and overall the thermal comfort conditions recorded during the measurement period were felt to be unacceptable.