<p>Renal arcuate vein thrombosis (RAVT) is a rare and often underrecognized cause of acute kidney injury (AKI) that typically requires renal biopsy for diagnosis. We report a 29-year-old man who developed AKI following heavy alcohol intake, an upper respiratory tract infection, and exposure to multiple medications including repeated nonsteroidal anti-inflammatory drugs and traditional Chinese patent medicines. Laboratory tests showed mild proteinuria without hematuria and negative autoimmune serology, with normal renal imaging. Renal biopsy revealed acute tubular injury and thrombus-like material within arcuate veins, accompanied by mild medullary hemorrhage and focal vascular necrosis, findings suggestive of arcuate venous thrombosis. Renal function recovered completely after supportive therapy within eight days.</p><p>This case highlights that an arcuate venous lesion suggestive of thrombosis may be an underrecognized finding in patients with multifactorial, biopsy-proven AKI, even when the clinical presentation and imaging findings are nonspecific. Awareness of this possibility may broaden the differential diagnosis in selected patients with unexplained or disproportionate AKI and multiple renal risk factors, and kidney biopsy may help identify otherwise unrecognized vascular involvement.</p>