This study describes the epidemiology of a range of adult musculoskeletal soft tissue injuries. Our institution is the only hospital treating adults with musculoskeletal trauma in a well-defined catchment population of about 535,000. Demographic details over 5 years were recorded prospectively. Eighteen injury types were studied including anterior cruciate ligament (ACL) rupture, acromioclavicular joint (ACJ) injury, Achilles, patellar and quadriceps tendon ruptures, hand tendon injuries and mallet finger. 2794 patients presented with ligamentous or tedinous injuries over 5 years. 74.2% of patients were male, giving an incidence of 166.6/100,000 per year for males and 52.1/100,000 per year for females. The mean age was 36.3 years: 33.1 in males, 43.6 in females. 1040 (37.2%) were knee injuries: 75.6% were male with mean age 32.9, compared with 35.3 in females. 947 cases were hand tendon injuries (33.9%): 72.1% were male, with mean age 34.5 compared with 42.0 in females. Meniscal injury of the knee was the commonest injury with an incidence of 23.8/100,000 per year. Other common injuries were hand extensor tendons (18/100,000 per year), ACJ injury (14.5/100,000 per year), Achilles tendon rupture (11.3/100,000 per year), mallet finger (9.9/100,000 per year) and ACL rupture (8.1/100,000 per year). Achilles, patellar and quadriceps tendon rupture and mallet finger were injuries of middle age; rotator cuff tears and biceps tendon rupture were commoner in the elderly but all other injuries predominated in young patients. All injuries were commoner in males. Most soft tissue injuries follow distribution curves previously described for fracture epidemiology but three new distribution curves are presented for the injuries which predominate in middle age.