Remarkable progress has been made over the past 30 years in understanding the flux of neutrinos coming from the sun. The so‐called “solar neutrino puzzle”, whereby the total number of electron neutrinos from the sun does not match the expected total neutrino yield can be now understood in the context of neutrino flavor transformations. The Sudbury Neutrino Observatory has contributed to understanding the solar neutrino problem by measuring both the electron and non‐electron components of the solar neutrino flux. The Sudbury Neutrino Observatory is a 1000 T D2O Cerenkov detector that is sensitive to8B neutrinos produced in the sun. By using the energy, radius, and direction with respect to the sun, the SNO experiment can separately determine the rates of the charged current, neutral current and electron scattering reactions of neutrinos on deuterium. Assuming an undistorted8B spectrum, thevecomponent of the8B solar flux is&fgr;e = 1.76−0.05+0.05(stat.)−0.09+0.09 (syst.) × 106 cm−2s−1based on events with a measured kinetic energy above 5 MeV. The non‐vecomponent is&fgr;&mgr;&tgr; = 3.41−0.45+0.45(stat.)−0.45+0.48 (syst.) × 106 cm−2s−1, 5.3&sgr; greater than zero, providing strong evidence for solarveflavor transformation. The total flux measured with the NC reaction is&fgr;NC = 5.09−0.43+0.44(stat.)−0.43+0.46 (syst.) × 106 cm−2s−1, consistent with the Standard Solar Model. A global solar neutrino analysis in terms of matter‐enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution. © 2003 American Institute of Physics