The authors discuss occurrence of post-radiation laryngeal oedema in the cases of patients with laryngeal cancer. The examination was carried out in 69 cases of patients on whom laryngectomy had been performed after failure of radiotherapy. In 65 out of these cases patients suffered from oedema of larynx with 57 cases classified as persistent or progressive post-radiation oedema (lasting for over three months inspite of application of pharmacological treatment), and 8 cases identified as fluctuating (receding after application of treatment and periodically reoccuring). Analysing the microscopic material of the specimens of the post-radiation oedema, the authors differentiated the stasis, inflammatory oedema and that causes by the presence of cancer infiltration. Basing on their own research data and the contemporary literature, the authors conclude, that the occurrence of persistent post-radiation oedema of the larynx lasting for the three months without reaction to the applied pharmacotherapy should be regarded as an important symptom signalling the presence or the recurrence of tumour after radiotherapy.