Chemoprophylaxis against tuberculosis with isoniazid for 1 year is very useful, but patient compliance is very low. A controlled clinical trial was performed to evaluate the efficacy of three alternative health education strategies and to observe which of them improves compliance with antituberculosis chemoprophylaxis in healthy tuberculin-reactor children. Although all three strategies achieved positive, statistically significant results as compared with the control group, that performed by nursing personnel at the patient's home is the most effective, followed by that performed by the same health professionals by telephone. The least effective strategy by far was that performed by the physician in his surgery.