Cleft lip is caused by the failure of the protrusions that form the lip in early embryonic life to grow together; to be precise, it is the unfused or incomplete fusion of the maxillary protrusion and the globus pallidus, which results in a unilateral cleft lip if one side is not fused and a bilateral cleft lip if both sides are not fused. Surgery is the only important method to repair cleft lip. Depending on the characteristics of the cleft lip and its severity, surgery is used to treat the deformity caused by the cleft lip. There are generally unilateral cleft lip and bilateral cleft lip. The most appropriate age for surgery for unilateral cleft lip is 3 to 6 months. Bilateral cleft lips are generally operated on from 6 to 12 months of age, and these surgeries are performed under general anesthesia and to restore the shape of the lip arch. The vast majority of patients who undergo cleft lip and palate surgery are infants and children, and general anesthesia is more risky than adult surgery and requires more adequate preoperative preparation. It is important for parents to be aware of the preoperative preparations that are necessary for a better surgery. The first step is to assess the child’s weight and nutrition, and to do a thorough health examination to see if there are any breaks or boils on the patient’s facial skin. If there is an infected lesion, treat it first and postpone surgery. For breastfed children, the family should start practicing feeding fluid juice or breast milk with a spoon or dropper 3 days before surgery so that the child can adapt to this type of feeding after surgery. Any anemia or dehydration prior to cleft lip and palate treatment needs to be corrected promptly. It is very important to prevent the occurrence of cleft lip. Women who are preparing to become pregnant should be educated about it and should pay attention to the proper distribution of nutrients and to the timely supplementation of nutrients in case of deficiencies. During pregnancy, it is important to avoid excessive stress and emotional excitement and to maintain a happy mood. Do not smoke, drink alcohol and avoid viral infections. In case of certain diseases, drugs that may cause fetal malformations should be prohibited.