A correlation is found between the sign of the magnetoresistance&Dgr;R=(RP−RAP)and the sign of the interlayer coupling in MnGa/(Mn,Ga,As)/MnGa trilayers (subscript P,AP=parallel,antiparallel magnetic alignment of both MnGa layers). Ferromagnetic coupling results in&Dgr;R<0,antiferromagnetic coupling results in&Dgr;R>0.This correlation has not been observed before and can not be explained by the usual model for giant magnetoresistance in magnetic multilayers. ©1997 American Institute of Physics.