The use of tisagenlecleucel has not been described in patients with <i>CHEK2</i> mutation.<h4>Case presentation</h4>We describe a case of a pediatric patient with a heterozygous pathogenic germline <i>CHEK2</i> mutation (c.1100delC; p.Thr367Metfs*15) successfully treated with tisagenlecleucel for relapsed B-ALL to avoid hematopoietic cell transplant (HCT). The gene discussed is CHEK2; the disease is precursor B-cell acute lymphoblastic leukemia.