The objective of this study was to determine the effect of place and type of initial treatment on survival from acute lymphocytic leukemia (ALL). Every one of the 327 children under 15 years of age diagnosed with ALL from 1970 to 1975 in a 31-county area designated the Greater Delaware Valley, were studied. Treatment according to protocol was associated with improved survival, yielding a 4 year survival of 60% vs 19% for nonprotocol treated patients (p less than 0.001). There was also a significantly improved survival rate among patients treated in a cancer center, especially for those with a low white blood count (WBC) at diagnosis. The prognostic importance of WBC, age, and sex was confirmed.