This is the third of a three-part article addressing whether physiotherapy involving pelvic floor muscle exercises (PFMEs) is efficacious as a first-line treatment for erectile dysfunction (ED). The first part (Vol 9(11): 691-4) highlighted the prevalence of ED, associated risk factors, the anatomy of the penis and the physiology of erection. The second part (Vol 9(12): 755-62) concentrated on the published clinical trials investigating the treatment and prevention of ED. This part will critically analyse the literature. PFMEs using ischiocavernosus muscles (ICMs) and bulbocavernosus muscles (BCMs) seem to have merit as a treatment for ED due to mild or moderate venous leakage. Men suffering from ED due to other causes may also benefit. There is no strong evidence that electrical stimulation or electroacupuncture is effective or ineffective. No studies demonstrating preventive conservative treatments were found. There is evidence that the ICMs and BCMs increase penile rigidity in the tumescent penis, that pelvic floor muscle efficiency is higher in potent men than impotent men and that perineal muscle efficiency reduces with age in impotent men. There is limited evidence that pelvic floor exercises relieve ED due to venous leakage and are a realistic alternative to surgery. Randomized controlled trials are needed to explore the use of PFMEs as a first-line treatment for men with ED.