Background: Sleep disorders such as insomnia may occur in old age, potentially leading to z-hypnotic use. However, few studies have explored older adults' self-reported sleep concerns in relation to z-hypnotic use. We aim to examine this relationship. Methods: We conducted a cross-sectional study using a web-based questionnaire to assess sleep disturbances and medication use (z-hypnotics, benzodiazepines, and opioid analgesics) among 5,194 older adults through 21 GPs in southeast Norway. The main outcome, inappropriate z-hypnotic use, was defined as self-reported use for >= 4 weeks at >= three times per week. We used descriptive statistics and exploratory logistic regression mixed-effects models for data analysis. Results: Among the 687 patients included in the study, 22% (N = 153) reported sleep disturbances. Of these, 84% (N = 575) did not use z-hypnotics, while 16% (N = 112) used z-hypnotics, 63% (N = 71) of these used them inappropriately. (>= 4 weeks, >= three times per week). Patients with sleep disturbances (OR: 12.1, CI: 6.77 - 21.6, p < 0.001), trouble falling or staying asleep (OR: 14.6, CI: 5.04-42.0, p < 0.001), and multiple reasons for disturbances (pain, overthinking, or a family death) (OR: 3.58, CI: 1.85-6.93, p < 0.001) had higher odds of inappropriate z-hypnotic use compared to those with no or occasional disturbances. Men had lower odds (OR: 0.54, CI: 0.30-0.97, p = 0.039) than women. GP prescribing was not associated with inappropriate use, but men had lower odds (OR: 0.34, CI: 0.14-0.84, p = 0.020) when prescribed by male GPs compared to women prescribed by female GPs. Conclusion: A high proportion of patients used z-hypnotics inappropriately. This inappropriate use was associated with experienced sleep disturbances, particularly trouble falling asleep, trouble staying asleep, and multiple reasons for sleep disturbances. The prescribing GP was not significantly associated with inappropriate use.