LEGAL prostitutes are just as happy as women with regular day jobs, according to a survey reporting high job satisfaction in parts of the sex industry.

But illegal workers who sell sex on the streets had a much grimmer outlook, with half saying they had been raped or bashed in the past year.

The unique survey compared the mental and physical health of nearly 250 Queensland prostitutes, aged 18 to 57, who worked in registered brothels, at home or streetside.

Legal workers reported similar job satisfaction to women in the general community, but streetworkers were far less happy in the job.

"The general picture is that those women whose families know about their work reported greater job satisfaction than those who kept their work secret", said researcher Charrlotte Seib.

Asked why they entered the industry, 82 per cent said they did it for the money and 52 per cent pointed to the flexible working hours.

"And 39 per cent said they had a particular goal in mind such as a new car, a house or a holiday," said Ms Seib, from Queensland University of Technology.

One in four of the women surveyed had a Bachelor degree or higher, which is contrary to the popular stereotype that sex workers came from socially disadvantaged backgrounds.

More than 60 per cent were employed before joining the industry.