A rapid new technique called T2 fast acquisition relaxation mapping (T2 FARM) was developed to allow T2 maps to be reconstructed directly from k-space data acquired in 3 sec. A single acquisition measured two sets of k-space data, the first with T1 and T2 weighting independent of phase encode position, and the second with T2 weighting varying with phase encode position. These data were processed using an iterative least squares algorithm to produce a quantitative T2 map from the k-space data. T2 values of phantoms and an egg were determined from T2 FARM maps and spectroscopic Carr-Purcell-Meiboom-Gill (CPMG) measurements, demonstrating the validity of the new technique.