1. The values for hemoglobin concentration, total white blood cells, granulocytes, lymphocytes and monocytes at the midpoint of 78 drug-induced remissions in a group of children with acute leukemia have been presented. These values have been compared with those from a group of normal children, and the differences analyzed statistically.
2. Statistical analysis shows that, in general, blood values in remission are reduced by the particular agent employed. White blood cells are more markedly affected than hemoglobin.
3. The effects are essentially the same with 6-M.P. given alone or in combination with azaserine or DON.
4. The reduction in values is greatest with 6-M.P., alone or in combination, less with amethopterin and least with prednisone.
5. The data presented indicate that criteria for complete blood remission should make allowances for the influence of the drug employed.