Certain phospholipids are associated with the nonhistone chromosomal proteins extracted from [human] normal B [bone marrow-derived] and chronic lymphocytic leukemia lymphocytes. The ratio of phospholipids to nonhistone chromosomal proteins was constant with the different methods used for isolating nuclei and extracting the chromatin, although the various methods allowed a different recovery of total lipids from chromatin. Three phospholipids were extractable from the nonhistone protein fraction, but their respective ratios varied in chronic lymphocytic leukemia compared to normal B lymphocytes. The most significant variation concerns the reduction of sphingomyelin content in leukemic lymphocytes, since this phospholipid in vitro affects DNA stability and transcription.