Campaigners said women are entering traditional female occupations such as hairdressing without realising these industries are the worst paid.
The study of 5,500 young people undertaking an apprenticeship in 11 industries found male trainees take home an average of pound;153 per week, compared to pound;113 for females. More than seven out of 10 trainees earning less than pound;80 per week were female and men were much more likely to be paid for overtime.
The lowest paid work was hairdressing at pound;90 per week and the highest in the electro-technical sector at pound;183. Ninety-three percent of the apprentice hairdressers were women while all those in the electro-technical sector were men.
Jenny Watson, acting chair of the Equal Opportunities Commission, called for improvements in career advice and better access for gitls to work experience in traditionally male occupations.
She said: "Young people should not have their career options and future pay limited by a lack of information. We know that eight in ten girls and over half of boys say they'd like to try a non-traditional career - yet fewer than 2 per cent of construction apprentices are female. The young people involved in our investigation were very clear that better information about pay levels would have prompted them to think again about their choices."
The gender pay gap is lower in sectors where there is a more even split between men and women. Male trainees in the hospitality industry earn an average 15 per cent more than women and those in retail take home 11 per cent more. Phil Hope, skills minister, said: "Youngsters need to make the right choices about the apprenticeships to take up, and knowing about potential earnings is a vital part of their decision.
"The research which covered the sectors with the highest numbers of apprenticeships will be available to Connexions advisers to ensure young people can be given more information about the pay in different sectors."