The prognosis in patients suffering from head and neck squamous cell carcinomas depends on many factors. However, regional lymph node metastases are the most important parameter in determining the cure and survival of patients with head and neck cancers. The evaluation of cancer cell biology enables differentiation of their proliferation and tendency of metastases. Immunohistochemical examinations complement the well-established routine histological examination. The aim of this study was to evaluate the prognostic importance of the level of immunoproliferating proteins such as cyclin D1, nuclear antigen Ki67 and suppressor gene p53 for regional lymph node metastases in laryngeal carcinoma. The research was carried out on 73 patients treated for squamous cancer of the larynx in the Department of Otolaryngology University School of Medical Sciences in Poznan in the years 1994–1999. The group was comprised of 4 female and 69 male patients. Their ages ranged from 37 to 79 years, with a mean of 59 years. Clinical data included sex, age, localization and local and regional extent of the tumor, presence or lack of distant metastases, treatment, histological examination as well as immunohistochemical evaluation of suppressor gene p53, proliferative proteins Ki67 and cyclin D1. No statistically significant correlation was found between staining intensity of suppressor gene p53, cyclin D1 and the degree of local advancement (T). There was no correlation between the level of immunoproliferative markers and regional lymph node metastases. Statistically significant correlation was found between T stage and staining for Ki67 (P=0.017) as well as between cyclin D1 level and Ki67 (P<0.05). In conclusion, (1) no significant correlation was found between Ki67 and cyclin D1, p53 and TNM classification; (2) lack of correlation was confirmed between N+, p53, Ki67, cyclin D1 and Jacobsson classification; (3) the degree of histological grading correlated, however, with Jacobsson classification and cyclin D1 expression. [ABSTRACT FROM AUTHOR]