The value of the routine chest roentgenogram was studied in 284 patients, newly admitted to our paediatric outpatient department. Emergency patients were excluded from the study. In 141 cases the initial diagnosis after history, physical examination and ECG was "no heart disease", while in 143 cases it was "heart disease". After a follow up of up to 4 years, 170 children appeared to have "no heart disease" and 114 definite heart disease. In 7.7% of cases the chest roentgenogram made at the first visit to the outpatient department led to a change in policy, whereas in only 3.8% was the chest roentgenogram in someway helpful in establishing the correct diagnosis. Amongst those children with initial diagnosis of innocent murmur, the chest roentgenogram led to a diagnosis of "heart disease" in only 2.8% of cases. It is concluded that for the differentiation "heart disease" or "no heart disease", a chest X-ray film is not indicated. In children with "heart disease" the chest X-ray film is also of little value, and is mostly to be used only for documentation.