根据加拿大内科医师和外科医师皇家学院的定义：儿科是与婴幼儿，青少年健康和疾病及其成长和发展相关的研究和护理医学分支机构，以及作为成年人充分发挥潜力的机会。

儿科医生是一名专门从事针对儿童广泛疾病诊断和治疗的专家，涉及儿童基于正常成长和发展的良好知识以及婴儿、儿童和青少年遇到的广泛临床状况。
As defined by the Royal College of Physicians and Surgeons of Canada: Pediatrics is that branch of medicine concerned with the study and care of infants, children and youth in health and disease, their growth and development, and their opportunity to achieve full potential as adults.

A pediatrician is a specialist trained in the diagnosis and treatment of a broad range of diseases involving children based on a sound knowledge of normal growth and development and of the wide range of clinical conditions encountered in infants, children, and youth.