To determine whether the appearance of a radial extracorporeal shock wave device affects clinical outcomes in chronic plantar fasciitis. Randomized controlled parallel assessor-blinded clinical trial. A total of 135 patients were assigned to 3 groups: group I, standard radial extracorporeal shock wave device; group II, standard radial extracorporeal shock wave device modified to give a more sophisticated appearance; group III, standard radial extracorporeal shock wave device modified to give a more austere appearance. The radial extracorporeal shock waves emitted by the 3 devices were identical. Primary outcome was foot function, measured with the Foot Function Index. Secondary outcomes were pain at different times, measured with a visual analogue scale, and plantar fascia thickness, measured with ultrasound. All variables decreased significantly from baseline assessment, in all 3 groups and at all time-points: 1, 2, 4 and 14 months after the last session (p < 0.001). There were no significant differences between groups for any of the variables assessed. Device appearance had no statistically significant influence on clinical outcomes in patients with chronic plantar fasciitis treated with radial extracorporeal shock wave therapy.