Objectives To compare custom-made insoles to sham insoles and general practice (GP)-led usual care in terms of pain at rest and during activity at 12 weeks follow-up in individuals with plantar heel pain. Methods In this randomised clinical trial 185 patients aged 18 to 65 years, with a clinical diagnosis of plantar heel pain for at least 2 weeks, but no longer than 2 years were recruited. Patients were randomly allocated into three groups: (1) GP-led treatment, plus an information booklet with exercises (usual care; n=46), (2) referral to a podiatrist for treatment with a custom-made insole plus an information booklet with exercises (custom-made insole; n=70) and (3) referral to a podiatrist and treatment with a sham insole plus an information booklet with exercises (sham insole; n=69). As well as the primary outcome of pain severity (11-point Numerical Rating Scale) we used the Foot Function Index (0 to 100) as a secondary outcome. Results Of 185 randomised participants, 176 completed the 12-week follow-up. There was no difference in pain or function between the insole and the sham groups at 12 weeks. Participants in the GP-led usual care group reported less pain during activity at 12 weeks, (mean difference (MD) 0.94, 95% CI 0.23 to 1.65), less first step pain (MD 1.48, 95% CI 0.65 to 2.31), better function (MD 7.37, 95% CI 1.27 to 13.46) and higher recovery rates (RR 0.48, 95% CI 0.24 to 0.96) compared with participants in the custom insole group. Conclusions Referral to a podiatrist for a custom-made insole does not lead to a better outcome compared to sham insoles or compared to GP-led usual care. Trial registration number NTR5346.