Low level laser therapy is being extensively used to treat various medical ailments including wound healing. In the present study, an optical fibre-based helium–neon (He–Ne) laser irradiation system was designed, developed and evaluated for optimum tissue repair on mice excision wounds. Circular wounds of 15 mm diameter were created on the dorsum of animals and single exposure of uniformly distributed laser beam was administered at 1, 2 and 3 J/cm² to the respective test groups with suitable controls. Progression of healing was monitored by measuring wound contraction and mean healing time. Significant reduction in wound size and mean healing time ($p < 0.001$) were observed in the test groups for the laser dose of 2 J/cm² compared to the unilluminated controls, suggesting the suitability of this dose.