This paper presents influence of selected prognostic factors on results of laryngeal cancer radiotherapy used as the only treatment in 541 patients irradiated in Centre of Oncology-Institute in Gliwice between 1990-1996. The 3-year actuarial disease-free survival was 47.5% for supraglottic cancer and 67% for glottic cancer. Primary tumour localisation in glottis correlates with more favourable prognosis than that in supraglottic. For extralaryngeal involvement the most favourable prognosis was infiltration of cartilages and the worst one for the hypopharyngeal and oropharyngeal involvement. Pretreatment tracheostomy significantly correlates with the worst results.