The family was denied refuge in Canada, and were deported back to Iran in December 2005 after exhausting all their legal avenues.
Kevin's parents, who say they were tortured and imprisoned in Iran, are expected to seek refugee status for a second time in Canada.
The Iranian parents of a nine-year-old Canadian boy tearfully thanked the Canadian Government for its efforts to win their release.
After spending six weeks in a Texas detention centre, the family arrived in Toronto Wednesday night.
It was the "worst possible experience," Majid added, standing next to his wife.
"There are almost 200 children that live there in very bad conditions. Now most of the children there have chicken pox, eye infection, flu."
Citizenship and Immigration Minister Diane Finley granted temporary passage to Canada.
The family was deported to Iran from Canada in December 2005 after living in Toronto for 10 years. The boy was born in Canada and is a Canadian citizen.
The family tried to return to Canada with the help of human smugglers, but were caught February 4th by US officials during an unscheduled stop on American soil.