Introduction/Objective. Success of guided bone regeneration depends on size and morphology of defect, characteristics of barrier membranes and adequate angiogenesis. The aim of the study was to reveal impact of three different collagen membranes on angiogenesis and bone production in critical size defects. Methods. Defects were created in rabbit calvarias, filled with bovine bone graft and randomly covered with one of three investigated collagen membranes (Biogide-BG, Heart-PC, Mucograft-MG) or left without membrane for control group (C). After two and four weeks of healing total of 10 animals were sacrificed for histological and histomorphometric analysis of angiogenesis, bone regeneration and inflammatory response. Results. In the early healing phase, the highest values of trabecular thickness and trabecular area were recorded with PC and BG membranes respectively. After four weeks significantly improved bone healing was noted in MG group, as well as significantly pronounced inflammation. Initially, vessel density was significantly higher in C group compared to all three membranes. After four weeks significantly better results were observed in MG compared to the other groups, BG compared to the rest of groups, and between PC and C groups. Conclusion. Use of collagen membranes significantly affects angiogenesis, reducing it in early and enhancing it at later healing phase. All three tested membranes in combination with bone graft significantly improved the amount of regenerated bone. Among the investigated groups MG favored more pronounced angiogenic, osteogenic and inflammatory response in observation period of four weeks.