Some 58 per cent of Generation X say it is major concern, placing it fifth in their list of stress inducers.
By comparison, work-life balance does not even make the top five concerns for Baby Boomers, who are more worried about the culture of their company and excessive corporate change.
Rebekah Haymes, senior consultant at Willis Towers Watson, said: "Work-life balance appears as a stronger stress driver for Generation Y employees, while the characteristics of the organisation play a more prominent role for older employees."
Despite pay being the top concern across the board, the research also found that younger staff have greater worries about their finances than older colleagues, with 64 per cent of Generation Y saying it is problem, 55 per cent of Generation X, but just 38 per cent of Baby Boomers.
But it is not the money in their wallets at the moment that is the biggest source of angst for the youngest workers; just 20 per cent of them say they are currently struggling to get by now. Instead long-term finances are a bigger concern as they see property prices rising further out of reach and ponder how they will finance retirement.