Detectives say more than 100 people were at the party when gang members opened fire.
Police have not yet made any arrests, but are hoping a $1 thousand reward brings someone with information forward.
The shooting happened before midnight Friday night on Van Ness and Vassar.
"It was like four or five of them were real rapid, bam bam bam, and then another four or five of them right after that," neighbor David Castro said.
Castro has lived in the quiet neighborhood for twenty years and was taken by surprise when he heard around a dozen shots.
"I ran outside concerned and there was people just running all over, just chaos, just running all over there street," he said.
Investigators say there were about 100 people outside on the street after the gun fire. Several party goers were seen leaving the scene before police arrived.
"As officers arrive at the house, there's over 100 party goers there, several gang members, West Fresno gang members were contacted and we had two shooting victims," Lt. Mark Salazar of the Fresno Police Department said.
Those two victims were taken to Community Regional Medical Center. Five more victims showed up at the hospital later - all had gunshot wounds said to be non-life threatening.
"We have not stopped investigating this case since it happened last night but right now we need leads - no one has come forward," Salazar said.
Authorities say half of the seven wounded are believed to be gang members. Neighbors are thankful no one was seriously injured but didn't expect something like this coming from that house.
"They're real nice people. I think it was just individuals wrong place, wrong time," Castro said.
Police are offering a $1 thousand reward for information that leads to arrests. Anyone with any information is urged to call the Fresno police department.