Abstract: A simple and accurate method for the separation and colorimetric determination of PABA in the aqueous solution of procaine has been described.The PABA may be extracted satisfactorily with ether at pH 3.6 using potasium bitartrate as buffer.The PABA extracted is condensed with.p-dimethylaminobenzaldehyde in the presence of acetic acid.The yellow color developed is measured in pulfrich photometer with filter S₄₇.