The research, which forms part of IFF Research's Attitudes to Work study, shows while 10% of employees believe that men are treated better than women at work, this figure increases to 19% when the question is asked of those working in organisations with fewer than 10 staff.
And views on gender discrimination differ significantly between the sexes. Some 15% of females think men are treated better in the workplace than women, with only 1% believing the reverse. Men hold a different and more balanced view, with 6% believing men are treated better and 5% thinking women come out best.
Among those believing men are treated better than women, over two-fifths say men are more likely to be promoted and nearly a quarter think men are paid more.
Mark Samuel, associate director at IFF Research, who headed the study, said: "Small businesses are often described as the engine room of our economy. It cannot be conducive to healthy working relationships, or our country's productivity, if 19% in these organisations - nearly twice the average for all employees - believe men are better treated than women.
"Nor is it good that women are substantially more likely to perceive male bias in the workplace, an issue back in the news after the employment tribunal equal pay ruling against Birmingham City Council.
"The truth about discrimination could be very different, but perception is all. Those working for small or micro businesses are likely to know everyone in the organisation and notice who's moving up the career ladder and who's not. Smaller organisations may have to go the extra mile to demonstrate to staff that they treat everyone equally. And all employers need to be aware of the gulf in attitudes between the sexes."