In the frame of the SIRGAS 2000 project the Venezuelan, Colombian and Brazilian vertical control networks were connected by spirit leveling and precise GPS height determination combined with a global geoid model. In the border zone between Venezuela and Brazil five benchmarks (BM) were included, each two of the Brazilian and the Venezuelan network, and one common to both networks. Along the Colombian — Venezuelan border, the connection was done in two different regions, the first one in the north at Maicao with three BM directly on the border line and the second one in the south at San Antonio/Cûcuta with each two BM on either side of the border. The height differences (AH) are about 3,45 m between the Brazilian and the Venezuelan leveling networks and about 0,3 m between Colombia and Venezuela, with opposite sign in the northern and the southern region. The comparison of the leveled heights (H) with the differences between GPS ellipsoidal heights (h) and EGM96 geoid undulations (N) shows maximum discrepancies (h-N-H) of 3,5 m in Brazil, 0,2 m in Colombia and 0,55 m in Venezuela.