['Photodynamic therapy (PDT) of actinic keratosis (AK) using methylaminolaevulinate (MAL) is an effective and safe treatment option, but the procedure is painful.', 'To evaluate the efficacy and pain associated with variable pulsed light (VPL), a prospective, randomized, controlled split-face study was performed.', 'Topical MAL-PDT was conducted in 25 patients with AK (n = 238) who were suitable for two-sided comparison. After incubation with MAL, irradiation was performed with a light-emitting diode (LED) (50 mW cm(-2); 37 J cm(-2)) vs. VPL (80 J cm(-2), double pulsed at 40 J cm(-2), pulse train of 15 impulses each with a duration of 5 ms, 610-950 nm filtered hand piece) followed by re-evaluation up to 3 months.', 'The pain during and after therapy was significantly lower with VPL irradiation [t (d.f. = 24) = 4.42, P < 0.001]. The overall mean +/- SD infiltration and keratosis score at 3 months after treatment was 0.86 +/- 0.71 (LED system) vs. 1.05 +/- 0.74 (VPL device) (no statistically significant difference; P = 0.292). Patient satisfaction following both treatment modalities did not significantly differ at the 3-month follow up (P = 0.425).'] Is variable pulsed light less painful than light-emitting diodes for topical photodynamic therapy of actinic keratosis : a prospective randomized controlled trial?