The introduction of our voluntary mass screening programme in 1971, in the province of Quebec, has permitted us to detect different inborn errors of metabolism in the newborn population using a thin‐layer chromatographic (TLC) technique with sequential use of different sprays on the same plate. Abnormalities in amino acids and organic acids are detected in urine filter paper specimens of 21‐day‐old babies. Initial parental compliance is 90% and climbs to 99.25% for repeat sample requests. Screening is centralized in one laboratory, while diagnosis, counselling, management and follow‐up are done in four regional centres. Over 25 inherited Mendelian disorders can be identified. There have been certain modifications in our programme throughout the years in order to increase efficiency, screen for a larger number of disorders, improve the quality of the collection of the urine filter paper samples, increase parental compliance and better manage the data bank. However, one goal has remained a priority: early prevention of genetic diseases. We present an overall view of our screening programme with an add‐on technique to detect different organic acidurias, our recent statistics and the modifications implemented over the years.