Aims To investigate whether thoracic exercises result in improved pain, range of movement and health-related quality of life (HRQOL) following open heart surgery (OHS), and to evaluate patient perception of the role of thoracic exercises in recovery. Methods A single-blinded pilot trial was conducted in a tertiary public hospital in Australia. Thirty-eight participants who underwent OHS were randomly allocated to an experimental (Group 1, n=23), or control (Group 2, n=15) group. All participants were prescribed a twice-daily walking programme postoperatively. The experimental group also completed a progressive, individualised thoracic exercise programme. Baseline pre-operative measures of shoulder and thoracic range of movement, pain and HRQOL were repeated at 4 weeks following discharge and 3 months postoperatively. Participants also rated their perceptions of the role of exercise and its contribution to physical recovery. Findings At 4 weeks following discharge, the experimental group reported 1.7 cm on the visual analogue scale (VAS) less sternal pain (95% CI of median 2.8–0.0, P=0.03) than the control group. The experimental group reported a trend toward greater perception of the contribution of their physiotherapy programme than the control group (median difference 1.2 cm, 95% CI -2.1–-0.0, P=0.04). There were no other differences between the two groups. Conclusions Thoracic exercises following OHS may be effective in reducing sternal pain and warrant further investigation.