SUMMARY: The objective of this study was to determine body composition, physical activity, and psychological state in postmenopausal women with osteoporosis. Fat mass, lean mass, water mass, and basal metabolic rate are lower, self-reported physical activity and risk factors of fractures are higher, and cognitive functions were worse in osteoporotic patients than in controls. Significant correlations were found between physical activity and emotional state parameters. INTRODUCTION: This study aims to determine peculiarities of body composition, physical activity, risk factors predicting fractures, psychological state and quality of life, and possible relations between them in postmenopausal women with osteoporosis in Lithuania. METHODS: Thirty-one postmenopausal women with osteoporosis and 29 healthy age- and sex-matched controls were included in the study. Profile of Mood State and Hospital Anxiety and Depression Scale were used for the assessment of emotional state. Trail Making Test and Digit Symbol Test of Wechsler Adult Intelligence Scale were used to evaluate cognitive functioning. Quality of life was evaluated using the World Health Organization Brief Quality of Life Questionnaire. Risk of fractures was assessed by the Risk Factors Predicting Questionnaire. RESULTS: Fat mass (22.4 +/- 4.7 vs. 40.6 +/- 14.2 kg, p < 0.001), lean mass (37.3 +/- 6.0 vs. 48.1 +/- 7.6 kg, p < 0.001), water mass (31.6 +/- 2.9 vs. 38.3 +/- 5.3 kg, p < 0.001), and basal metabolic rate (1,253 +/- 132 vs. 1,456 +/- 126 kcal, p < 0.001) were lower in osteoporotic patients than in controls. Self-reported physical activity (2.35 +/- 0.6 vs. 1.69 +/- 0.5, p < 0.001) and risk factors of fractures (5.9 +/- 2.1 vs. 2.6 +/- 2.4, p < 0.001) were higher in women with osteoporosis than in healthy age- and sex-matched controls (2.35 +/- 0.6 vs. 69 +/- 0.5, p < 0.001). Trail making A and B scores were higher in patients than in age- and sex-matched controls (55.8 +/- 19.9 vs. 45.1 +/- 19.9, p = 0.07 and 118.2 +/- 34.6 vs. 92.8 +/- 48.7, p = 0.006). Some significant correlations were detected between physical activity and emotional state and quality of life parameters. CONCLUSION: In postmenopausal women with osteoporosis, fat body mass, lean body mass, water body mass, basal metabolic rate, and waist-to-hip ratio are lower, physical activity and risk of fractures are higher, and cognitive functions are worse than in age- and sex-matched controls. Some psychological peculiarities could be related to physical activity in women with osteoporosis.