The country ranks the worst out of all island Pacific nations in the US State Department's Trafficking in Persons Report 2015.
The Marshall Islands' poor record revolves around the capital Majuro's role as a port of call for foreign fishing and transhipping vessels.
It says Marshall Islands girls are recruited by foreign business owners to engage in prostitution with crew members of the vessels.
It also says some Chinese women are recruited with promises of legitimate work and forced into prostitution after paying large recruitment fees.