Cerebrospinal fluid leukocytes from 48 apparently healthy New Zealand white rabbits were examined to define the number and types of cells present. The cerebrospinal fluid contained 0 to 7 leukocytes/mm3 (median 3/mm3). This small pool of mononuclear cells was comprised of 40 to 79% lymphocytes (median 67%) and 21 to 60% monocytes (median 33%). T lymphocytes were the predominant cell type, outnumbering B cells by approximately 100 to 1. In contrast to cerebrospinal fluid, normal rabbit blood contained nearly equal proportions of B and T cells (median 39% and 46% of lymphocytes, respectively). Three cerebrospinal fluid samples from apparently healthy rabbits had greater than 20 leukocytes/mm3.