BACKGROUND Although several studies have been performed on the use of various devices in total shoulder arthroplasty (TSA), no data are available in order to establish whether to prefer stemmed or stemless humeral components. Thus, the purpose of our study was to evaluate the short-term functional outcome in a cohort of subjects treated with TSA randomized to treatment with stemmed or stemless prosthesis. METHODS In this prospective longitudinal study, we randomized to treatment with stemmed (group 1) or with stemless (group 2) humeral component in nineteen subjects (2 M and 17 F) diagnosed with humeral primary osteoarthritis with indication to TSA. We evaluated the range of movement of all the participants and the functional outcome using Constant score and simple shoulder test (SST) before and after 2 years from surgery. RESULTS No differences were detected after 2 years from surgery in the two groups in terms of functional scores and range of motion (p > 0.05). CONCLUSIONS Stemmed and stemless prostheses are comparable in terms of functional outcome. These data might be useful for the surgeon in order to choose more tissues-paring methodologies and less invasive procedures, such as stemless humeral implants.