INTRODUCTION: Laryngeal cancer, especially in the advanced stages, is a highly devastating disease, characterized by increased invasiveness and high rates of metastasis. Gelatinases A and B (MMP-2 and -9 respectively) are of particular interest due to their contribution to various stages of carcinogenesis. There is a growing body of evidence with regard to the prognostic value of certain MMPs and their possible role as tumour markers.AIM: To identify the pattern of alteration of serum gelatinases A and B in patients with laryngeal cancer following treatment, and a possible correlation with various clinicopathological parameters.MATERIALS AND METHODS: Forty nine patients were included in this study. Pre-treatment and post-treatment serum samples were collected and processed by gelatin zymography and western blotting.RESULTS: Only the latent forms of MMP-2 and -9 were identified. Both gelatinases were increased in the serum of laryngeal cancer patients compared to healthy individuals. Patients with supraglottic tumours and active smokers had significantly higher pre-treatment levels of proMMP-2 than patients with glottic tumours (p < 0.05) and ex-smokers (p < 0.05), respectively. Patients with primary disease and patients with lymph node involvement showed lower serum proMMP-9 pre-treatment levels than patients with recurrence (p < 0.05) and patients without neck disease (p < 0.1), respectively. During the follow-up period the proMMP-2 serum levels increased significantly in the first ten to fifteen days after treatment, gradually decreasing over the following months. The proMMP-9 serum levels showed a gradual decrease after treatment, which was statistically significant (p<0.05).CONCLUSIONS: The post-treatment alteration pattern of proMMP-9 serum levels shows a possible role of this molecule as a tumour marker in laryngeal cancer. Further research is necessary to clarify the contribution of both gelatinases to the disease progress and determine their role as prognostic factors and tumour markers.