He was 66 and is survived by wife and two sons, state BJP executive member and Patel's close confidant Om Soni said.
Patel, who had suffered a heart attack sometime back and had recovered, this morning complained of uneasiness and was rushed to the district hospital where he died during treatment, Soni said.
According to Soni, doctors said Patel suffered a cardiac arrest.
The BJP had nominated Patel from the Rajpur (ST) seat in the first list of candidates announced on November 2.
Madhya Pradesh will have a single phase polling on November 28.
Patel served as a minister of state in the Cabinet of former chief minister Uma Bharti, BJP sources said.
A multiple times MLA, the BJP leader first entered the assembly in 1990. He then won three assembly elections in a row from Rajpur - in 1998, 2003 and 2008.
In 2013, he lost to Congress candidate Bala Bachchan.
Both Patel and Bachchan were given ticket from Rajpur from their respective parties for the November 28 elections.
His last rites will be performed at his native village Bandarkachh in the district, the sources added.