Summary: An histological study of the behaviour of subcuticular green polyglycolic acid (GPGA) suture was undertaken to investigate if the green dye is retained by macrophages or histiocytes. Fifteen rats had subcuticular closure of a dorsal incision with GPGA suture. The closure site was excised at intervals and examined by light and electron microscopy. There was no evidence of dye retention, but a brisk inflammatory reaction was noted.