This paper describes the results of an analytical study of linear and nonlinear behaviour of ductile coupled shear walls with openings, under seismic loading. The walls in a typical building were studied and assumed to be ductile. They were designed, calculated, and detailed in compliance with the National Building Code of Canada 1990 (NBC) and the Canadian concrete code CAN3-A23.3-M84. The results of the elastic analysis show, as expected, that the concentrated force at the top specified by the NBC does not accurately simulate upper-mode effects, at least for this type of structure. A spectral analysis covering the five first modes, as described in the NBC, seems more suitable for coupled shear walls with openings with a period of more than 1.5 s approximately. The results of the nonlinear analysis show that application of the overstrength factor to the wall as recommended by CAN3-A23.3 greatly improves its behaviour and prevents tensile failure of the wall, although it does not always guarantee the desired sequence of plastification in the case of severe earthquakes. Application of the factor does, nonetheless, limit plastification of the wall to lower levels and keeps rotational ductility in beams and walls to a reasonable level.Key words: coupled shear walls, openings, reinforced concrete, ductility, overstrength factor, earthquake, building codes.[Journal translation]