Radial forearm flap is a gold standard for oral soft tissue defect reconstruction after tumour ablative surgery of oral cancer in advanced stages. The main disadvantage of this flap is donor site morbidity. The goal of our study was to show versatility of lateral arm flap in 34 cases with different oral defects that were reconstructed after tumour ablation, and to analyse complications and donor site morbidity. Thirty-four patients with advanced stage oral cancer (T3 and T4) underwent tumour ablation with or without suspicious lymph node removal and with immediate reconstruction of oral defect with lateral arm flap. Analysis of complications and donor sites morbidity was carried out. The Michigan Hand Outcome Questionnaire was used to evaluate functional and esthetical donor site outcome during at least one year follow up. Thirty-one patients had successful free flap surgery with uneventful post-surgery period. Flap loss due to vascularity problems was in one case (2.9%). The flap success rate was 97.1%. The donor site was closed primarily in all cases and healed uneventfully. The Michigan Hand Outcome Score was average 94.30%. The lateral arm is an excellent choice for oral reconstruction after ablative tumour surgery. It is versatile, safe and reliable for oral reconstruction with very good functional and aesthetical donor site outcome.