Objective To investigate whether gender is associated with use of hypnotics or sedatives and with different types of hypnotics or sedatives in older people after adjustment for age, socioeconomic status (i.e., education) and co-morbidity (i.e., number of other drugs). Setting Sweden Method We conducted a register-based analysis of data on gender, age, dispensed drugs, and education from people aged 75-89 years registered in the Swedish Prescribed Drug Register between July and October 2005 (n = 645,429). Main outcome measure The hypnotic or sedative drug classes were benzodiazepines, benzodiazepine related drugs (i.e., Z-drugs) and other types of hypnotics or sedatives. The individual hypnotics or sedatives were nitrazepam, flunitrazepam, triazolam, zopiclone, zolpidem, clomethiazole and propiomazine. Results In the total study population, 27.1% of the women and 18.1% of the men were dispensed at least one hypnotic or sedative drug. The logistic regression analyses of those who used hypnotics or sedatives (n = 151,700) revealed that women were more likely than men to use benzodiazepines (adjusted OR = 1.11; 95% CI 1.07-1.14) and benzodiazepine related drugs (adjusted OR = 1.14; 95% CI 1.12-1.17), whereas men were more likely to use other types of hypnotics or sedatives (adjusted OR = 0.69; 95% CI 0.67-0.71). Among the individual hypnotics or sedatives, the strongest associations with gender was found for nitrazepam (adjusted OR = 1.19; 95% CI 1.14-1.25 for women compared with men), zolpidem (adjusted OR = 1.18; 95% CI 1.16-1.21), clomethiazole (adjusted OR = 0.48; 95% CI 0.46-0.51) and propiomazine (adjusted OR = 0.77; 95% CI 0.75-0.79). Conclusion Use of hypnotics or sedatives in old age seems to be related to female gender. Also, among elderly users of hypnotics or sedatives, women appear to be more likely to use benzodiazepines and benzodiazepine related drugs than men. The explanation to these gender differences merits further investigation.