Background Primary squamous cell carcinoma of the kidney is very rare, with only eight cases reported to date. We describe herein what we believe is the first case of hepatic invasion of a primary squamous cell carcinoma that originated in the kidney. Case Presentation A 73-year-old asymptomatic man was referred to our hospital for further evaluation after an abdominal ultrasonography revealed a right renal mass. Contrast-enhanced computed tomography (CT) showed a hypodense mass with capsular enhancement from the upper pole of the right kidney to the right lobe of the liver. Ultrasonography-guided renal biopsy was performed to identify the origin of tumor. The pathology indicated a squamous cell carcinoma, but it was unclear whether it was a primary carcinoma of the kidney or a metastatic growth derived from other organs. Chronic fever appeared and the patient’s general malaise worsened day by day. Contrast-enhanced CT one month after the previous one showed rapid growth of the right renal tumor and progressive hepatic invasion. Radical nephrectomy and hepatic resection of the posterior segment by laparotomy was performed. Pathological analysis indicated the origin of this tumor was tubular epithelium, and the patient was diagnosed with primary squamous cell carcinoma of the kidney, pT4. Conclusions This case showed that squamous cell carcinoma of the kidney can invade the liver, and this cancer can progress very rapidly, on a daily basis. When hepatic invasion of renal squamous cell carcinoma is suggested, combined renal-hepatic resection should be considered. In addition, once this disease is suspected, surgery must be performed as soon as possible, considering the speed of its progression.