The cause of Scott Disick's parents death has not been widely publicised. They were both 63 years old and died within three months of each other.
Jeff Disick died on 10th January 2014 in a nursing home in LA. The cause of his death is also officially unknown however, there is speculation that he died of cancer because when Scott met a cancer patient named Josie just before his father's death, he confided in her that his dad was also ill.
That said, there is a quote on NY Daily News.com that says:
"Seeing Josie confront her illness really made me think about my dad —
who suffers from diabetes and needs a heart replacement — I really don't
talk about it because it's so hard for me,"
So that suggests that his death could have been caused by either his heart problem or even the diabetes.
I can't begin to imagine how Scott feels after losing two parents at a young age within such a short time frame, especially as he is an only child.