Moraxella lacunata (M. lacunata) is a Gram-negative bacterium, which rarely causes serious infection. This is a rare case report of acute glomerulonephritis diagnosed by pathological findings in a child accompanied by M. lacunata infection. The patient showed hematuria, proteinuria and hyperkalemia requiring emergency hemodialysis. After hospitalization, M. lacunata bacteremia became apparent. Pathological findings showed an increase in glomerulus inflammatory cells and glomerular C3 deposition was observed in the renal tissue biopsy. Final diagnosis was endocapillary proliferative glomerulonephritis. Clinical reports of M. lacunata infection requiring emergency hemodialysis in children are rare. Previous reports have suggested that lowered immune competency with chronic kidney disease may be a risk factor associated with serious invasive cases of M. lacunata infection. However, detailed clinical laboratory data and pathological findings have not been identified in previous case reports. Our case directly indicated complement activity and acute glomerulonephritis with M. lacunata infection. Although there are various causes for acute glomerulonephritis, infection-related glomerulonephritis (IRGN) is an important concept. M. lacunata infection might have a potential risk for IRGN with dysregulation of complement activity leading to serious and invasive clinical conditions than previously considered.