Ex-President Goodluck Jonathan and former military President Ibrahim Babangida are not at the ongoing council of state meeting in the presidential villa in Abuja on Thursday.
Also absent are former President Shehu Shagari and Ernset Shonekan, ex-interim president.
The council of state is the highest constitutional advisory body in Nigeria.
This is the third council of state meeting under President Muhammadu Buhari. Three former heads of state are in attendance.
They are Yakubu Gowon, Olusegun Obasanjo and Abdulsalami Abubakar.
The former chief justice of Nigeria in attendance are Mohammed Uwais, Idris Kutigi, Alfa Belgore and Aloma Mukhtar.
The opening prayers were said by Gowon and Uwais.
The meeting is focusing on issues of insecurity in the country as well as the coming elections in 2019.
Officials from Independent Electoral Commission (INEC) are around to brief the council.
Obasanjo, who was five minutes late, rushed when a minute silence was being observed in honour of Dahiru Mustapha, former chief justice of Nigeria.
The meeting, which began at 11:05am, is also being attended by Vice-President Yemi Osinbajo; Senate President Bukola Saraki and Abubakar Malami, attorney-general of the federation.