Immunization is an important measure for preventing infectious diseases that should be administered from an early age to boost children’s immunity against various dangerous diseases. One of the mandatory basic immunizations for infants is the Bacillus Calmette-Guérin (BCG) vaccine, which aims to prevent tuberculosis (TB). Following BCG vaccination, a scar typically forms at the injection site as a sign of the body’s immune response to the vaccine. This study aims to determine the characteristics of BCG scars in children aged ≤ 1 year recorded in the KMS at the Posyandu in the Raja Basa Indah Public Health Center, Bandar Lampung City, in 2013. The study used a descriptive survey method with an observational approach. The study population consisted of 707 children, and the sample comprised 88 children selected using simple random sampling. Data collection was conducted through direct observation of the presence of BCG scars on the children’s right upper arms and documentation based on the Health Development Card (KMS). Data analysis was performed using univariate analysis with SPSS version 16 and presented in the form of frequency distributions. The results showed that of the 88 children who had received BCG immunization, 67 children (76.1%) developed a BCG scar, while 21 children (23.9%) did not. The development of a BCG scar is influenced by several factors, such as the injection technique, vaccine dose, vaccine quality, and the child’s immune system. This study shows that most children who have received the BCG vaccine develop a scar as a sign of successful immunization.