Aims A pragmatic multicentre randomised controlled trial (PROFHER) was conducted in United Kingdom National Health Service (NHS) hospitals to evaluate the clinical effectiveness and cost effectiveness of surgery compared with non-surgical treatment for displaced fractures of the proximal humerus involving the surgical neck in adults. Methods A cost utility analysis from the NHS perspective was performed. Differences between surgical and non-surgical treatment groups in costs and quality adjusted life years (QALYs) at two years were used to derive an estimate of the cost effectiveness of surgery using regression methods. Results Patients randomised to receive surgical intervention accumulated mean greater costs and marginally lower QALYs than patients randomised to non-surgery. The surgical intervention cost a mean of £1758 more per patient (95% confidence intervals (CI) £1126 to £2389). Total QALYs for the surgical group were smaller than those for non-surgery -0.0101 (95% CI -0.13 to 0.11). The probability of surgery being cost effective was less than 10% given the current NICE willingness to pay at a threshold of £20 000 for an additional QALY. The results were robust to sensitivity analyses. Discussion The results suggest that current surgical treatment is not cost effective for the majority of displaced fractures of the proximal humerus involving the surgical neck in the United Kingdom’s NHS. Take home message: The results of this trial do not support the trend of increased surgical treatment for patients with displaced fractures of the proximal humerus involving the surgical neck within the United Kingdom NHS.