It was retrospectively examined whether the tumor growth fraction determined by PCNA score in the advanced cancer of larynx could be used as a prognostic factor. There was used immunohistochemical method to evaluate the PCNA score of positive cells in paraffin embedded tissues of laryngeal carcinoma obtained from 90 patients. They were treated by surgery in the Department of Otolaryngology at the Medical University in Cracow, Poland in 1987 and 1988. The follow-up period was not shorter than 5 years. In the examined material there were 59 patients with tumor T3 and 31 with T4. Neck dissection on one or on both sides was performed on patients. The metastases in regional lymph nodes was found in 26 patients. Histologic grading (G1 = 18, G2 = 52 and G3 = 20 patients) and number of mitosis was assessed. The PCNA score was defined by counting positive cells and presented as percentage of a cells. It ranged from 2.1 to 73.0% with the average value of 34.5%. The PCNA score below this level was defined as a low PCNA score (49 patients) and above this level as a high PCNA score (41 patients). There was a correlation between PCNA score and survival of the patients. 35 patients (71.4%) with low PCNA score survived and 15 (36.6%) with high PCNA score (P < 0.05). Similarly the high PCNA score influenced the number of metastases in lymph nodes. They occurred in low and high PCNA score respectively at nine (18.4%) and 17 patients (41.5%) (P < 0.05). There was not found any correlation between PCNA score and tumor differentiation, its size and mitosis number. The PCNA may be a prognostic factor for the patients with advanced cancer of larynx.