OBJECTIVES: The impact of exclusive human milk diet (EHMD) on postnatal growth remains controversial. This study aims to investigate the association between EHMD and short-term growth. METHODS: This multicenter retrospective study aims to compare growth between the EHMD and non-EHMD groups among infants <32 weeks of gestation. Primary outcomes include weight, length, and head circumference growth trajectories between birth and 34 weeks postmenstrual age. Sensitivity and subgroup analyses were performed. RESULTS: An EHMD was independently associated with poorer length growth, especially in infants born at ≥28 weeks' gestation or those exposed to hypertensive disorders of pregnancy. While initiating fortification at <26 kcal/oz on an EHMD showed inferior growth, initiating fortification at ≥26 kcal/oz was associated with improved weight growth, and similar length and head circumference growth when compared to the non-EHMD group. CONCLUSIONS: An EHMD with initial fortification at ≥26 kcal/oz may be implemented to avoid bovine milk exposure while sustaining comparable growth.