This chapter addresses the considerable stresses created within women's communities and the 'women's sector' by the determination of male-bodied transgenders to access women's services as workers, clients and members. It examines the implications of such demands in relation to women-only contexts created specifically out of second wave feminism to serve the particular interests of women as a subordinated group. The chapter consider the implications of the demand by men who transgender, continue to be heterosexual after transition, and proclaim themselves to be lesbians, to access lesbian-only spaces. It begins with the challenge to women-only social space, as exemplified in the Michigan Womyn's Music Festival, and move on to the challenge to women's services. As a result of transgender entryism, women's services in many countries are having to devise policies to deal with a new problem. When the services were set up in earlier decades, male-bodied transgenderism was a much less significant phenomenon in size and in legal clout.