The necessity of long-term venous access in cancer patients appears at frequent and long-term courses of cytotoxic therapy. Peripheral veins of forearms are most often used for these aims. The conditions of peripheral venous channel in 32 cancer patients, who underwent the long-term treatment with antitumor preparations were analyzed in the article on own investigatory material.The methods of dopplerography, morphological and immunohystochemical studies were used. The qualitative and quantitative dopplerographic changes in forearm veins in different terms after chemotherapy start were revealed in most patients. The conclusion was made about unsuitability of forearm peripheral veins for the long term administration of cytostatics and the necessity to create the alternative vascular access that would correspond to the criteria of safety, reliability and long-term exploitation.