Patients with precursor-B-cell acute lymphoblastic leukemia (B-ALL) may initially present with a prodrome, cytopenia(s) with abnormal bone marrow cellularity, but without clonal abnormalities. Prior cases of “indolent ALL” report infections preceding B-ALL diagnosis. Here we describe our institutional experience, eight patients over a 15-year period with a prodrome (2% of B-ALL diagnoses) prior to definitive diagnosis. Patients ranged from 3-15 years of age (median 5 years), requiring a median 3.5 months from presentation to diagnosis, with a median 3 bone marrow aspirates (BMA) to reach definitive diagnosis. Practitioners must be aware that initial negative BMA does not rule out B-ALL.