Swimsuits will almost certainly have to be made from textiles from January and men are poised to return to trunks, swimming's governing body, FINA, said on Friday.
Controversy over performance-enhancing bodysuits made from non-textiles has overshadowed the swimming world championships, which start on Sunday.
"The material is to be textile," FINA executive director Cornel Marculescu told a news conference after a congress meeting.
"In general it is going to be short trunks. But let us finish the rules."
The details of the new rules will be thrashed out at another meeting on July 28 but full bodysuits will remain for these championships.
FINA has come under criticism for its failure to regulate the rapid advances in swimsuit technology that has led to 108 world records last year and nearly 30 so far this year. Some suits are suspected of creating "air trapping" effects that artificially enhance speed.