The author's visit on 8th and 9th of Bahman 1402 to the area of the Strait of Hormuz and the islands of the Persian Gulf led to a re-examination of the risk of an earthquake and the possibility of a tsunami caused by it on the coasts of the mainland and the islands of the Persian Gulf. The Persian Gulf coast is a region that faces various natural hazards, one of the most important of which is tsunami and earthquake. In the Persian Gulf, the probability of a tsunami is less compared to the Oman Sea. Large landslides can cause tsunamis if they occur on the sea floor. The severe earthquakes of 978 and 1008 that happened in the Siraf region, near the current Taheri port and Asaluyeh, were accompanied by a tsunami. Historically, there are evidences that indicate the occurrence of tsunamis in the Persian Gulf region.