In 11 cases of megaloblastic, achylic anemia with subacute combined degeneration of the spinal cord, the author has estimated the blood contents of cholesterol and the blood and cerebrospinal fluid contents of phospholipids (in lecithin) and inorganic phosphorus, before and after treatment with vitamin B12. The estimations have been correlated to the hematologic condition. The mean amounts estimated show normal blood cholesterol, increased blood phosphatides and cerebrospinal fluid inorganic phosphorus and decreased blood inorganic phosphorus in neuroanemia; the study of each case shows that the cases of more severe anemia exhibited the lowest levels. After treatment, all the mean amounts increase. Individually, it is evidenced that the variations are generally concordant; the hematologic improvement is followed by a rise of the blood contents of cholesterol and phospholipids and, less consistently, by increase of the blood and cerebrospinal fluid inorganic phosphorus.