The voice is one of the most essential tools necessary for nurses achieve high care satisfaction and safety. Research on hoarseness has mainly focused on professional speakers, like teachers. The aim of this study was to determine the current prevalence of hoarseness among six subgroups of nurses (registered nurses, primary care nurses, pediatric nurses, laboratory nurses, dental nurses, and midwives) and also to identify potential environmental risk factors in their working environment. The health data was collected in collaboration with two health care professional trade unions. The findings are based on 15,553 returned health questionnaires which were statistically analyzed. The 1-year prevalence of hoarseness among all participating nurses was 30.2 % in this data, but the variation between different occupational subgroups was significant; ranging from 25 % for laboratory nurses to 38 % for midwives. These findings were in line with perceived environmental problems and the differences between the sub-groups were not explained by the participants suffering from asthma, sinusitis, rhinitis, or common respiratory infections; there were no explanatory differences in the prevalence's of the above-mentioned diseases. The variation in prevalence of hoarseness between the different occupational subgroups was significant and the prevalence was found to be in line with perceived environmental problems. The most common problems were stuffiness, dry air, and inadequate ventilation. In addition, both a perceived "sewer odor" and "smell of mold or cellar" in one's own working environment were also found to be significant risk factors for hoarseness. Based on this study, the current indoor air problems in Finnish health care facilities can be verified and are a source of risk to nurses' voices.