Sajwani started his career in 1981 in the finance department in Abu Dhabi Gas Industries. Two years later, he started a catering venture, with customers including the U.S. military and Bechtel. The venture is still operational and is now called Global Logistics Services.

In 2002, Sajwani established DAMAC Properties, one of the largest property development companies in the Middle East. The company has delivered around 27,400 homes since its inception and has over 35,000 units under various stages of development.

In October 2011, DAMAC Properties launched its hospitality division, ‘DAMAC Maison Hotels & Resorts’. In 2015, the company was publicly-listed with shares traded on the Dubai Financial Market.

In 2017, the Hussain Sajwani – DAMAC Foundation sponsored Dubai Future Foundation’s One Million Arab Coders Initiative, which was launched by UAE Vice President and Prime Minister, and Ruler of Dubai, Sheikh Mohammad bin Rashid Al Maktoum, to provide free software development training to one million young Arabs.

In February 2020, the foundation pledged AED 3 million to the Arab Hope Makers initiative’s Humanitarian Cause of the Year – the construction of the Magdi Yacoub Global Heart Centre in Egypt.

In April 2020, the Hussain Sajwani-DAMAC Foundation pledged Dh 1 million to the ’10 million meals’ campaign, UAE’s biggest food distribution drive for those affected by the coronavirus.