Three of the five were independents and the others were the candidates of a registered political party, the Chief Electoral office said here.
Chacko George and Soman Pillai P filed papers as independents from Thrissur, while Sasikala filed her papers from Pathanamthita.
Biju and Shajar Khan of SUCI filed their papers from Kottayam and Thiruvnanthapuram respectively.
The last date for filing nominations is March 22 and scrutiny is on March 24. The last date for withdrawing nominations is March 26.
The main political fronts in the state are Congress led United Demoratic Front, CPI(M) headed Left Democratic Front and the BJP.