Abstract Introduction: Immunoglobulin G4-related kidney disease (IgG4-RKD) is a recently identified inflammatory disorder most often classified as IgG4-related tubulointerstitial nephritis or IgG4-related membranous nephropathy based on the predominant renal pathology. However, almost all the cases are complicated by extrarenal organ involvement that includes lymph nodes, pancreas, lacrimal glands, salivary glands, and/or retroperitoneum. IgG4-RKD with cirrhosis as the initial presentation followed by massive proteinuria and renal dysfunction is very rare. Patient concerns: A 35-year-old Chinese male presented to a local hospital with abdominal distension, edema, and black tarry stool 5 years before. Abdominal color ultrasonography at that time suggested cirrhosis, and the diagnosis was upper gastrointestinal hemorrhage with decompensated cirrhosis. About two weeks before, edema was aggravated, and massive proteinuria and renal impairment were detected with significantly elevated serum IgG. Abdominal computed tomography indicated cirrhosis and diffuse renal enlargement with multiple low-density foci, while light microscopy of renal biopsy tissue indicated atypical membranous nephropathy with interstitial nephritis. Immunohistochemistry revealed 20–50 IgG-positive plasma cells per high-power field among interstitial infiltrating cells, accounting for ∼40% of all IgG-positive plasma cells. Diagnoses: According to clinical manifestations and immunohistochemical findings, the diagnosis was IgG4-RD/IgG4-RKD featuring atypical membranous nephropathy, interstitial nephritis, and decompensated cirrhosis. Interventions: Methylprednisolone 40 mg/day was administered for IgG4 related kidney disease. Other symptomatic therapies were also administered. Outcomes: Half a month following the treatment, 24-hour proteinuria decreased from 10.67 g/d to 2.16 g/d and serum creatinine decreased significantly. Conclusion: IgG4-RKD with cirrhosis as the first manifestation followed by renal dysfunction is very rare. Simultaneous occurrence of these two conditions which improved after the treatment indicates that there may be an association between IgG4 related kidney disease and cirrhosis.