A 14-year-old boy diagnosed with primitive neuroectodermal tumor of the L5 vertebra defaulted from his treatment, which significantly contributed to the progression of his disease. The possible causes of defaulting were (1) poor doctor/patient rapport, (2) inadequate communication between doctor and patient about the disease and its treatment, (3) unavailability of a "no show" defaulters' compliance program and case managers, (4) patients' economic constraints, (5) additional inconveniences because of referrals and consultations in a large multispecialty state-run hospital, and (6) patient's low education level and poor understanding of the disease and its treatment. Defaulting is multifactorial but can be contained. Good doctor/patient rapport, with emphasis on effective communication is important in improving compliance. Institutional administrative procedures should be more user-friendly. Medical institutions should consider having a "no show" defaulters' compliance program and case managers in those specialties where defaulting can adversely affect the clinical outcome.