The results of the use of Proplast, a new alloplastic material, in experimental middle ear surgery are described. This material was tested for cavity obliteration, closure of bony defects and as a columella between the tympanic membrane and the medial wall of the middle ear. Proplast was well tolerated in the middle ear cavity even in cases with inflammation of the middle ear. The implants were integrated within the recipient tissue by fibrous ingrowth occurring within one week. Bony ingrowth was observed in those cases where the implant contacted the bony wall within 3 weeks. Proplast which supported the tympanic membrane was infiltrated by fibrous tissues and incorporated in the lamina propria. No significant side effects were observed in a 6‐month follow‐up period although a possible influence on bone remodeling could not be fully exclu