Aim | Benzodiazepines and Z-drugs are frequently prescribed sleep medications in spite of their poor risk-benefit ratio when used over a longer period of time. The aim of the study was to find out how the medical and nursing staff in a general hospital estimated the frequency of use for these drugs, and the risk-benefit ratio for elderly patients as well as the factors which positively influence the perceived use of these drugs. Methods | All members of the medical and nursing staff of a hospital received a questionnaire about their use of, and attitudes towards, benzodiazepines and Z-drugs. Absolute and relative frequencies were calculated to estimate the perceived frequency of use and the risk-benefit ratio. Multiple logistic regressions were used to analyze which factors are associated with a perceived high use of benzodiazepines or Z-drugs for insomnia. Results | More nurses than hospital doctors believed that they dispensed benzodiazepines often or always (57 % vs. 29 %) to patients with insomnia; this was also the case for Z-drugs (66 % vs. 29 %). Nearly half of the hospital doctors and 29 % of the nurses perceived more harms than benefits for benzodiazepines in the elderly. The following factors were associated with a high perceived usage of Z-drugs: working as a nurse (OR: 13,95; 95%-CI: 3,87-50,28), working in a non-surgical department (5,41; 2,00-14,61), having < 5 years of professional experience (4,90; 1,43-16,81) and feeling that the benefits of Z-drugs outweigh the risks for elderly patients (5,07; 1,48-17,35). For benzodiazepines, only the perceived positive risk-benefit ratio had an influence on the perceived use (3,35; 1,28-8.79). Conclusion | The medical and nursing staff perceived the frequency of prescription of benzodiazepines and Z-drugs and the risk-benefit ratio in different ways. Other aspects, such as working in a non-surgical department or having a smaller amount of working experience may also influence the decision to use Z-drugs.