The protection of exposed children (EC) is one of the cornerstones of tuberculosis (TB) control. There are limited information about chemoprophylaxis (CP) compliance in Chile and worldwide. We evaluate this situation in South Eastern Metropolitan Health Service located in a poor district, providing free care for more than 400,000 children. We enroll in this study all kids under five years old, living in close contact with TB all forms patients. The children were referred between 2003 and 2005 to the Pediatric Pneumology Unit. Our TB contacts management protocol considers four visits: The first one for CXR, sputum smear (BAAR) and tuberculin (PPD 2 UT). The 2nd on is for diagnosis. The 3rd one3 month follow up to check compliance and repeat PPD if previously negative; and 6 mo CXR for discharge. We indicate QP with isoniacide (HIN) 5 mg/k/day for 6 mo to all exposed (CXR and BAAR negative independently of PPD). We stop QP on visit 3 if index case became BAAR (-) and if PPD is (-) twice. We follow with QP to all PPD (+) children till 6 mo. Primary Care Centers had the responsibility to administer HIN weekly to parents. Compliance was evaluated verifying attendance to follow up in the Pediatric Unit. TB index case patients were 123, they had 318 exposed children, were excluded 21: moved houses 6; developed HIN allergy 2; non pulmonary TB contacts PPD (-) 11; secondary cases 2 (in DOT). At the second visit (diagnosis), 27 children quit (8%). 270 left for analysis. At the third visit, 160 turned up (59%) and 136 turned up for the 6 mo checkup (50%). It is possible some degree of inaccuracy in the information provided by parents about drugs administration but is clear that in our environment, compliance is deficient and increase with length of chemoprophylaxis