The BBC, citing a study carried out by Which? Holiday magazine, says that passengers have rated Heathrow's Terminal 1 as the worst place to travel from.
Only 31 percent of the 9,000 people questioned said they were satisfied with services at the west London airport.
Terminals 2, 3 and 4 were listed as the next least popular, followed by Gatwick Airport's two terminals.
BAA, which owns both airports, said it planned to invest $8.5 billion over the next five years to improve infrastructure.
London City airport was rated second best in the survey, after Blackpool's airport, while Heathrow's Terminal 5 came midway in the poll.
About a quarter of all passengers said they found the experience of traveling through an UK airport stressful, but in the case of Heathrow Terminal 1, the figure was between 38 and 45 percent.
About 19 percent of those surveyed said they felt intimidated by security staff at Terminal 2.
Many passengers rated signs and flight details at Heathrow Terminals 1 to 4, Manchester's Terminal 1 and Coventry airport as poor.
But Heathrow's new Terminal 5, which faced criticism for its chaotic opening last year, fared better in the survey; 54 percent of people said they were satisfied with services there.
Regional airports won accolades, with eight out of 10 travelers saying they were happy with services at Blackpool airport, followed by London City airport at 78 percent, Doncaster Sheffield (76 percent) and Southampton 71 percent.