Mother's milk (ASI) is the most perfect food containing the nutrients needed by babies to fulfill the baby's needs, growth and development. Head circumference measurements are often used to indicate brain size and volume. The aim of this study was to determine the relationship between the duration of breastfeeding and the head circumference of babies aged 1-7 months in the working area of the Kuala Lempuing Health Center, Bengkulu City. The design used was a cross sectional approach on 43 samples of babies who met the inclusion criteria. Head circumference measurement data was obtained using a measuring tape, duration of breastfeeding was collected by interviewing mothers using a 14-item closed-ended questionnaire. The 43 samples obtained were taken using the Purposive Sampling technique. The Spearman correlation test was used to analyze the relationship between variables. The average duration of breastfeeding for babies aged 2 months, with babies aged 1 month receiving the most breast milk. The average head circumference is 40.12 cm with an average of 40.34 cm for male babies and 39.90 cm for female babies. The results showed a significant relationship between the duration of breastfeeding and head circumference in babies aged 1-7 months in the working area of the Kuala Lempuing Community Health Center, Bengkulu City in 2024 (p=0.000) and shows a positive direction (r=0.623) which means the longer the breastfeeding period, the more normal the head circumference will be. In conclusion, prolonged breastfeeding will be related to the size of the baby's head circumference

Baby, Duration of Breastfeeding, Head Circumference