Methods to obtain specimens from children are invasive, and the procedures require skill. Because children are smaller and weaker than adults, the procedures often become difficult. The equipment for the procedures must be chosen based on the physical constitution of the patient. In addition, pediatric patients often do not cooperate with procedures, and so restraint of the patient is extremely important. It is particularly important when obtaining specimens from small neonates and infants, after establishing the minimum quantity of specimens, to choose an appropriate procedure. Because the state of the patient may change suddenly during procedures, staff present during the procedure must always confirm vital signs, and prepare for breathing and circulation management. Pediatricians frequently perform blood sampling, urine collection, and cerebrospinal fluid collection in daily clinical consultation. These techniques are introduced in this report.