In Iran, Iran Air Company entered its fleet of four Boeing 737 series 200 ordered in the early 1950s. A ceremonial 200 series aircraft had also entered the country before the revolution for the then government of Iran. After the revolution, two more aircraft from the 200 series [refugees from Iraq] flew in the sky of our country for a while. This content is copied from Tayareh's blog.

In the mid-seventies, Iran Air negotiated with Boeing for the purchase of 16 Boeing 737 400 series aircraft and related spare parts, but due to the opposition of the American government, these negotiations did not reach a conclusion. Also, in line with the agreement on Iran's nuclear program, Iran Air Company and Aseman Company were supposed to purchase 30 737 MAX airplanes from Boeing, but these contracts were not completed with the withdrawal of the United States from the JCPOA.

Until the early 1990s, except for the original IranAir Boeings and a few limited short-term leases of the Boeing 737 by Aseman and Taban companies, this aircraft had no other presence in Iran, until the middle of 2013 and with the openings that took place due to the JCPOA negotiations, the Caspian Company By importing 5 Boeing 737 400 series planes, he opened the way for this plane to enter Iran.

Real Photo:

Credit to @CL125's for his original Boeing 737-400 Malaysia Airlines.
Credit to @XAircraftManufacturer's for his original XJ-737-400