Immediate and late follow-up results of oncomammological application of novel Ukrainian endoprosthesis “Nubiplant”, made of one piece of polyacrylamide gel, for mammary gland malignancies (MGM) radical treatment with reconstruction were analyzed. This endoprosthesis have proved its unique complex of favorable surgical and oncological properties, such as the shape and size accommodation for mammary gland plasty purposes, absence of shell and textured surface. Of 184 patients, operated on radically for initial stages of MGM, using “Nubiplant” endoprosthesis, postoperative complications have had occur in 18 (9,8%): the wound seroma in 12 (6,5%) and partial necrosis of cutaneous edge of postoperative wound – in 6 (3,8%). The seromas were successfully treated by their punctures and local necrosis using excision with secondary suture placement. Late follow-up results were obtained in 112 (60,9%) patients: three-year period have had survived 104 (92,6±2,4%), and a five-year one – 84 (75,0±4,0%) of them. A contracture capsule was revealed in 3 (2,6%) patients, and excised with the endoprosthesis change. “Nubiplant” endoprosthesis have advantages over most popular worldwide kinds of such products. It may be used securely and effectively for total or partial reconstruction of mammary gland, including cases with hypoplasia, and is more resistant to trauma, radiation therapy and local complications occurrence, including contracture capsule formation. Its property to absorb the water may be used for purposes of plastic surgery. Prophylaxis of specific immediate surgical complications is trustworthy in MGM patients, using modified endoprosthesis “Nubiplant”, containing insulin, antihistamine and antiseptic medicines.