The authors explain the second phase in surgery procedure which is known as intra-operative, developing a standardized model of nursing care for children and adolescents during the intra-operative phase. This phase commences in the operating room from the moment the child/adolescent arrives after being brought from a hospital ward and lasts until the child/adolescent is transferred to the recovery room. The authors perform a systematic and holistic evaluation, using the Gordon Functional Health Patterns. The authors select the Nursing Diagnoses of NANDA, the North American Nursing Diagnosis Association, which most frequently appear in this intra-operative phase: risk of lesion, risk of infection, risk of hypothermia, and risk of asphyxiation. The authors also mention the potential complications which could appear during an operation according to the age of the child, the type of anesthesia used, the surgical technique used, and the overall health of the patient prior to surgery. Finally, the authors describe the nursing treatments related to the potential complications and the outlined nursing diagnoses.