Green fluorescent protein (GFP) is widely used as an excellent reporter molecule in biochemistry and cell biology. Some biochemical and immunological assays require high-purity GFP. However, the majority of current procedures for GFP purification include multiple time-consuming chromatography steps with a low yield of the desired product or require tag-containing proteins. An alternative method is described for the GFP purification without affinity extensions using organic extraction yielding a highly homogeneous protein indistinguishable in spectroscopic properties from that purified by previous methods.