Polling stations opened at 0700 BST on Thursday and closed at 2200 BST
Voters were locked in at some West Midlands polling stations while others were turned away in an effort to control crowds at closing time.
Police were asked to disperse queues outside St Paul's Church, Birmingham, and provide crowd control at Mere Green polling station in Sutton Coldfield.
Birmingham's returning officer Stephen Hughes said officials tried to process as many votes as possible.
He said the poll closing time had been clearly marked on all polling cards.
Long queues and angry scenes have been seen at polling stations around the country.
Mr Hughes said: "People have had 15 hours to vote, everyone knows that polling stations close at 10pm - it is clearly marked on polling cards.
"There have been a couple of polling stations where we've had to lock the doors, but we have endeavoured to get as many people in as possible and process them."
Voting has taken place in 25 West Midlands constituencies.
Karl Wilkinson, who lives near St Paul's Church polling station in Birmingham's Jewellery Quarter, said queues began forming from 1800 BST.
He said many people who were trying to vote in the Birmingham Ladywood constituency had to be turned away at 2200 BST.
He added: "A huge number of voters in this area are young professionals who feel strongly about their right to vote.
"It seems that Birmingham City Council has let us down once again by providing a facility that was wholly inadequate."
Charles Duncan said: "There were queues literally around the block so it took us 55 minutes to vote.
"We came out just after half past nine and the queue had actually got longer."
Ch Insp Debra Doyle said: "There were large numbers queuing outside (St Paul's) and people were getting irate, but there was no disorder."
She said it was up to the presiding officer to decide when to close the doors and police helped to calm down the situation and disperse the crowds.
She estimated about 100 people were turned away from St Paul's. She said most people in Mere Green had been able to vote.
The Electoral Commission said it would be undertaking a "thorough review" of what had happened in constituencies around the country where people were unable to vote.
Meanwhile local council elections are also taking place alongside the general election in some areas. However, votes may not be counted until Friday.