Substituted benzoxazine and 3,4-dihydrobenzoxazine derivatives possessing activity as estrogen receptor beta (ER) modulators are provided which have the structure of formula I ##STR1##

• wherein the substitutents are as described herein.

In addition, a method is provided for preventing, inhibiting or treating the progression or onset of pathological conditions associated with the estrogen receptor and to pharmaceutical compositions containing such compounds.