Passengers described the dancer, photographed by a passenger's mobile phone, as a "well-dressed, attractive, student-like young woman".
She apparently performs her routines only when there is time the train is traveling between distant stations in the Romanian capital.
Her modus operandi is to play Tom Jones's You Can Leave Your Hat On on a portable CD player while taking off her clothes and dancing around a pole.
She then puts her clothes back on and passes around a container for passengers to show their appreciation for her efforts.
A police spokesman said the woman faced charges and a fine for indecent exposure and public begging if she is caught in the act, however, her performances seem well planned as she performs only on trains with no guards or CCTV cameras.