Samajwadi Party president Mulayam and his party general secretary drove to the residence of Lok Janshakti Party leader Ram Vilas Paswan, where they met for nearly 30 minutes.
Rashtriya Janata Dal leader Lalu Prasad, also a part of the new alliance was, however, not present as he was in Patna.
After the meeting, Singh told media persons that the Fourth Front will decide on the future course of action after the results are out on May 16.
"We will decide and come up with a strategy. The alliance is not restricted to the elections. It will continue post-poll," Singh, flanked by both Yadav and Paswan, said.
When asked about the absence of the RJD chief, he said "Prasad is in Patna. We spoke to him over telephone."
Singh, however, evaded questions on the Fourth Front's Prime Ministerial candidate. "No comments," he said to queries on the alliance's stand on PM candidate.
Exit polls have projected that the United Progressive Alliance will get 190 to 205 seats and the National Democratic Aliance 185 to 196 in the 543-member House and Third Front at a little over 100 seats.