The transcription factor GATA-2 is expressed in hematopoietic stem and progenitor cells and is functionally implicated in their survival and proliferation. In the present study, we show that GATA-2 exists as an acetylated protein in immature precursor cells, KG1. GATA-2 was acetylated in vitro by p300 and GCN5. We have identified multiple acetylation sites by p300 on GATA-2, which include sites outside the zinc finger domain. We confirmed that GATA-2 acetylation occurred in transiently transfected 293T cells at sites similar to those induced by p300 in vitro. We have successfully shown that acetylation of GATA-2 in vitro increased its DNA-binding activity. In addition, GATA-2 displayed a transcriptional synergism with p300 that was impaired by mutation of each acetylation site. More importantly, each mutation in the acetylation sites of GATA-2 abolished its growth inhibitory effect on an interleukin-3-dependent progenitor, 32D. We conclude that acetylation provides multiple control points for the regulation of GATA-2 function.