Microwave ablation (MWA) is a new technology developed in recent years, which is widely used in various disciplines. Microwave ablation is an alternative to surgery in the management of various tumors, and it has been demonstrated to be effective in the management of primary tumors and metastatic tumors. Microwave ablation is widely used in the treatment of hepatocellular carcinoma with an obvious effect and less side effects, and only 2.7% had serious complications. Many studies have confirmed the complications are thermal damage, hemorrhage, pleural effusion, bile leak, tumor seeding, hepatic abscess, cholangitis, and so forth. But diaphragm perforation is rare, and it is probably the first case reported. This article describes diaphragmatic perforation secondary to MWA of the liver with subsequent pleural effusion and diaphragmatic hernia. We also describe its management via the laparoscopic approach.