Abstract Background The aim of this study is to determine the knowledge and awareness of adult individuals applying to the Family Health Center (FHC) about osteoporosis. Methods A descriptive design study was conducted at a FHC in Turkey/Istanbul between January and May 2022. The sample of the research consisted of 320 adults selected by purposeful sampling method. Ethical approval and necessary permissions were obtained from the the conduct of the study. Data were collected through a socio-demographic characteristics form, a 20-item single-subscale Osteoporosis Knowledge Assessment Questionnaire (OKAQ), and a 27-item Osteoporosis Awareness Scale (OAS). Descriptive statistics, normality tests, analysis of variance, Kruskal-Wallis analysis of variance, t-test, and Mann-Whitney U test were used for data analysis. Statistical significance was accepted at p < 0.05. Results T The average age of adults is 60.47±13.17 and 55.9% are female and 44.1% are male. 34.7% had completed middle school. Participants’ highest correct response rate in the osteoporosis knowledge assessment questionnaire was for the item ‘Osteoporosis increases the risk of bone fracture’ (81.6%), while the lowest correct response rate was for the item ‘Osteoporosis generally causes symptoms (such as pain) before fractures occur’ (26.3%). According to the Osteoporosis Awareness Scale, adults’ awareness levels were above average. They scored the highest in the preventive behaviors subscale and the lowest in the risk factors subscale. Adults with university-level education scored significantly higher in all subscales of the OAS compared to other education levels (p < 0.05). Individuals with knowledge about osteoporosis and those who consumed milk regularly scored significantly higher in all subscales of the OAS (p < 0.05). Conclusions Although adults’ awareness of osteoporosis is above average, their correct knowledge about osteoporosis is inadequate. Key messages • An individual’s education level affects osteoporosis knowledge and awareness. • It is recommended to plan educational initiatives to increase osteoporosis knowledge and awareness.