Resin is a natural product of coniferous trees. Salves manufactured from spruce resin (Picea abies) have been used for centuries to treat wounds and skin infections. We report a pilot clinical trial designed to investigate healing rates, factors that contribute to delayed wound healing, cost-effectiveness, and incidence of allergic reactions when resin salve is used to treat complicated surgical wounds. The trial involved 23 patients in whom wound healing after surgery was delayed. These patients were assigned to resin salve treatment. The primary outcome measure was the number of days to complete wound healing. Secondary objectives included an assessment of factors contributing to delayed wound healing, an estimation of associated costs, and an investigation into the occurrence of allergic reactions related to resin salve therapy. The study achieved a healing rate of 100%. The mean ± SD healing time was 43 ± 24 days. The mean ± SD wound size (length × width × depth) was (29 ± 19) × (12 ± 7) × (4 ± 3) mm. Wound size, use of corticosteroids or other immunosuppressants, and immobilization were statistically significant (P < 0.05) contributors to delayed wound healing and impaired re-epithelialization. The total mean ± SD costs of the resin salve treatment were €45.0 ± 26.0 per patient during the entire treatment period and €1.2 ± 0.5 per treatment day. The rate of allergic reactions was 0%. The results of this pilot trial indicate that complicated surgical wounds may be treated successfully with resin salve. The treatment method is clinically effective and cost-effective, and the rate of allergic reactions is low.