Osteogenesis imperfecta (OI) is a connective tissue disease with bone fragility. Several studies have indicated that physical function in adult OI was correlated to the disease severity, but there have been no reports delineating the impact of the fracture characteristics and disease-specific complications on health-related quality of life (HRQoL). The purpose of this study is to clarify the factors impacted on HRQoL in adult OI patients. We conducted a cross-sectional study between July 2016 and March 2018 and sent a questionnaire regarding HRQoL using Short Form-36 (SF-36) to the OI patients at the age of 20 years or older who had a medical history of the investigators' institutions. The 40 patients completely answered the SF-36. Mental component summary and role/social component summary were unremarkable. Physical component summary (PCS) was significantly associated with z-score for height, teeth abnormality, and cardiopulmonary insufficiency (partial regression coefficient, 3.04, - 9.70, and - 11.35; p, < 0.001, 0.047, and 0.025, respectively). PCS was also significantly lower in the patients who had an initial fracture before the age of 2 years than those without occurrence of fractures until 2 years old (25.80 ± 17.15 versus 44.20 ± 16.54; p = 0.002), or those who had lower extremity fractures more than five times as compared with normal populations. Physical function was decreased in OI patients who had fractures before 2 years old, especially in lower extremity. Appropriate medical managements for cardiopulmonary insufficiency are required not only to maintain physical function but also to decrease mortality.