Al-Mashaan founded the ALARGAN International Real Estate Company in 1994. The publicly traded company operates in Kuwait, Oman, Morocco, and Bahrain. It focuses on residential, commercial, health, education, and hospitality projects. It had developed projects worth $2 billion and projects under development worth $792 million. The company reported total assets worth $785.3 million as of September 2023, and its market cap amounted to $57.5 million as of November 14, 2023. Its portfolio includes ARGAN Business Park, Al Bustan Residences, and Telal Al Qurm. Al-Mashaan is also a chairman of the Kuwait Green Building Council.