Currently, the spread of coronavirus has affected almost the world and all cities in Iran. In this regard, the present study was conducted to analyze the rate of cases and mortality due to the COVID-19 virus in Iran and the world. Moreover, a comparison was made between the mortality rates due to COVID-19 and the 34 leading causes of mortality worldwide. A fourth-degree polynomial ARIMA model was applied to examine the variable death cases in Iran and the world. Reviewing monthly statistics in Iran has shown that in a period of 11 months, from February 19, 2020, to January 19, 2021, the country has encountered three major peaks of corona-infected cases. In Iran, the highest number of active and dead cases were detected from November 21 to December 20, 2020, with 330,007 and October 22 to November 20, 2020, with 12,550 individuals, respectively. However, a worldwide survey showed that the highest number of active and dead cases were found in North America and Europe in December 2020. Implementation of two periods of complete quarantine [February 21–December 20, 2020 and November 12–December 1, 2020] have had a great impact on reducing coronavirus infections and deaths in the following months in Iran. Among 34 well-known major causes of death reported worldwide, COVID-19 was ranked 8th, 19th, 15th, 3rd, 32nd, and 2nd in Africa, Asia, Europe, North America, South America, and Oceania, respectively. The analysis of death cases obtained from the ARIMA model showed an increasing trend with significant volatility, indicating that measures taken to cope with outbreaks such as widespread quarantine have not been successful enough. The general trend of death in Iran is similar to that of the world, while for the World, it shows more significant volatility. Due to the various consequences of this virus, statistical analysis of the number of infected cases and deaths in Iran and the world might be helpful to better understand the factors affecting coronavirus spread and decision-making for control mechanisms of the virus.