Purpose: The identification of early relapse in children treated for acute lymphoblastic leukemia might further improve the cure rate, although no hard data in support of this prospect are available at present. Unfortunately, many of the newer approaches to this challenge are not widely available in less developed countries. We tested the hypothesis that persistent abnormalities in simple hematologic parameters of peripheral blood, after treatment of ALL, may predict the subsequent recurrence of disease. Patients and Methods: Charts were reviewed from all patients in a single institution who were in their first continuing complete remission for at least 6 months after completion of therapy. Palpable splenomegaly, Hb, MCV, WBC, ANC, ALC, Platelets and MPV were recorded thereafter at consecutive 6-month and subsequently annual intervals. Data in the non-relapsing children were compared to those in relapsers using Fisher's Exact Test. Additionally, the normalization times of hematologic parameters after therapy were recorded for both groups. Results: Of 104 patients, 7 relapsed. Those who had more than one abnormal parameter at 6 months after therapy were significantly more likely (p = 0.02) to have a subsequent relapse than those in whom this was not the case (Specificity 98%, Negative Predictive Value 95%, Diagnostic Accuracy 93%). There were no significant differences in the mean normalization times of the study variables between the non-relapsers (8 weeks) and relapsers (5 weeks). Conclusions: While results of this study are statistically significant, the frequency of the abnormalities and the interval between their discovery and the subsequent recurrence of disease do not suggest that simple blood counts are clinically useful as a means of detecting relapse of ALL. A study with a larger sample size should be conducted.