The quality of ultrasound imaging to examine anatomical structures in the wrist and hand has improved highly over the last years. The value of ultrasonography (US) performed by hand surgeons on treatment decisions was investigated in this study. One hundred and ninety-five patients with an unclear clinical hand problem were evaluated by high-definition ultrasonography from January 2005 until June 2007. In 21% of cases, the procedure and therapy were influenced by the ultrasonographic findings. In 26 patients examined by ultrasound, surgery was avoided, while 14 patients had unexpected ultrasound results that led to surgery. In 22 of the 84 performed operations, ultrasound had a direct impact on the surgical procedure itself. The agreement of the ultrasonographic diagnosis and the post-operative diagnosis (n = 80) was better, though not statistically significant compared to the agreement between clinical diagnosis and diagnosis after operation (n = 84). Ultrasound imaging performed by the hand surgeon improves quality in the evaluation of hand problems. Ultrasonography is a cost-effective high-resolution investigation with the possibility of dynamic imaging.