Chronic occupational manganese (Mn) overexposure is associated with motor and cognitive deficits, but its effects on hippocampal subfields remain underexplored. Although neurodegeneration is known to involve the hippocampus, subfield-specific structural abnormalities have received limited attention. This study aimed to assess the diagnostic power of hippocampal subfield volumes in discriminating asymptomatic Mn-exposed welders from healthy controls (HCs). Mn-exposed welders and age-matched HCs w