The GALLEX Collaboration reports the results of their solar neutrino experiment using a 100-ton gallium chloride target solution at the Gran Sasso Underground Laboratories. The experiment, known as GALLEX IV, ran from February 14, 1996, to January 23, 1997, with 12 solar runs and 5 blank runs. The main result from GALLEX IV is [118.4 ± 17.8 (stat.) ± 6.6 (sys.)] SNU (1σ), or 118.4 ± 19 SNU (1σ) after subtracting contributions from side reactions and Rn background. The combined result for all 65 solar runs (GALLEX I-IV) is [77.5 ± 6.2 (stat.) ± 4.3-4.7 (syst.)] SNU (1σ). The GALLEX experimental program has now concluded, and the Gallium Neutrino Observatory (GNO) project, with new goals and targets, has taken over in April 1998. The results from GALLEX are consistent with previous experiments and validate the solar neutrino detection capabilities of the GALLEX detector, suggesting that the 7Be solar neutrino flux is significantly below what is expected from standard solar models, leading to the conclusion that neutrino mass must be considered.The GALLEX Collaboration reports the results of their solar neutrino experiment using a 100-ton gallium chloride target solution at the Gran Sasso Underground Laboratories. The experiment, known as GALLEX IV, ran from February 14, 1996, to January 23, 1997, with 12 solar runs and 5 blank runs. The main result from GALLEX IV is [118.4 ± 17.8 (stat.) ± 6.6 (sys.)] SNU (1σ), or 118.4 ± 19 SNU (1σ) after subtracting contributions from side reactions and Rn background. The combined result for all 65 solar runs (GALLEX I-IV) is [77.5 ± 6.2 (stat.) ± 4.3-4.7 (syst.)] SNU (1σ). The GALLEX experimental program has now concluded, and the Gallium Neutrino Observatory (GNO) project, with new goals and targets, has taken over in April 1998. The results from GALLEX are consistent with previous experiments and validate the solar neutrino detection capabilities of the GALLEX detector, suggesting that the 7Be solar neutrino flux is significantly below what is expected from standard solar models, leading to the conclusion that neutrino mass must be considered.