The aim of this study was to evaluate whether a fracture of the proximal humerus is associated with an increased prevalence of preceding fractures or a risk of subsequent fractures. All patients who were treated at the Malmö General Hospital in 1987 for a fresh fracture of the proximal humerus were identified, representing practically all fractures of the proximal humerus in Malmö city (250,000) that year. Two hundred fifty-three adult patients, 54 men with an average age of 66 (24-90) and 199 women with a mean age of 74 (22-98) years, were included in the study together with 475 age- and gender-matched control persons. In 1999, fracture prevalence of patients and controls were rated by a survey at the Dept. of Radiology. There was a significantly increased prevalence of previous fractures before 1987 in the humerus fracture group with an odds ratio (OR) of 3.5 [95% confidence interval (95% CI), 2.2-5.5] for a spinal fracture, OR 1.8 (95% CI, 1.3-2.6) for a previous fracture to the upper extremity, and OR 1.8 (95% CI, 1.2-2.6) for a preceding fracture of the lower limb. The proximal humerus fracture also predicted a significantly increased risk of a subsequent fracture. The hazard ratio (HR) was 2.5 (95% CI, 1.7-3.7) for a forthcoming spinal fracture, HR 2.8 (95% CI, 2.0-3.7) for a future fracture of the upper extremity, and HR 2.0 (95% CI, 1.2-3.5) for a lower limb fracture. In a subgroup of male patients, an almost five times increased risk of sustaining subsequent extremity fractures was observed. In summary, a fracture of the proximal humerus is associated both with increased prevalence of previous fractures of the spine and extremities and also predicting an increased risk of future fractures.