Aim: To investigate the common flexor tendon (CFT) thickness and the frequency of ultrasound (US) pathological alterations in its structure in a healthy population and to evaluate if these findings can be correlated with dominant hand ; age ; gender, body mass index, workload, menopause status. Material and methods: The study population consisted of 111 healthy volunteers. Bilateral CFT thicknesses were measured at 5 mm, 10 mm and 15 mm distance to medial epicondyle. Tendon echotexture, tears, calcification, enthesophyte, and neovascularization were also evaluated. Results: The CFT was thicker on the dominant side at all three locations (2.1 versus 1.9 nun proximal, 4.0 versus 3.7 mm in the middle and 7.0 versus 6.6 mm distal, all p<0.05). 'thickness correlated negatively with postmenopausal duration in all landmarks, except for the nondominant side distal part and positive with body mass index, significantly on the dominant side proximal and middle parts. A statistically significant correlation was found between heavy workers group and tendon thicknesses on the proximal and middle parts of the dominant side and the distal part of the non-dominant sides. US tendinosis was detected in 24/222 tendons, calcification in 11/222 tendons and enthesophyte in 33/222 tendons. The threshold age was 46.5 years for enthesophytes and 51.5 years for calcifications. The prevalence of calcification and enthesophyte tended to be higher in blue-collar workers and on the dominant side. Conclusions: The CFI thickness varies depending on measurement locations, handedness, body mass index, postmenopausal duration and workload. The US signs of tendinosis may be encountered in a symptom-free population. Calcification and enthesophyte tended to be more frequent in blue-collar workers.