Since 1984, laboratory tests have not been routinely required for healthy paediatric patients scheduled for one-day surgery in our Paediatric Surgery Department. We reviewed the medical charts of all children ASA physical status 1 and 2 who underwent a minor surgical procedure in the last 15 years. We excluded all former preterm infants of less than 60 weeks postconceptual age. The series under examination includes two groups of patients: group A includes 1884 children who underwent routine preoperative laboratory tests; group B includes 8772 children who had preoperative, selected laboratory tests performed only when the child's history and/or clinical examination revealed some abnormalities. The following data were collected: demographic data, ASA physical status classification, surgical procedure, anaesthetic technique, major and minor complications, length of hospital stay, the difference between the expected length of hospitalization and the actual length, number and reasons for cancellations of surgery. On the basis of our experience we believe that a thorough clinical assessment of the patient is more important than routine preoperative laboratory screening, which should be required only when justified by real clinical indications. Moreover, this practice eliminates unnecessary costs without compromising the safety and the quality of care.