As established by Eurocode 3, the verification of member stability should be carried out considering imperfections and second order effects. Two procedures may be used for this purpose: (1) second order analysis of members with local imperfections, and (2) buckling resistance analysis. If second order analysis is carried out, applied moments and moments due to initial bow imperfection are properly amplified in the presence of compression forces. Consequently, only cross-section resistance checks are needed. Eurocode 3 provides two ways for defining design values of initial imperfections: the traditional e0/L coefficient and the theoretical expression used to obtain EC3 buckling curves. On the other hand, buckling resistance of members subjected to bending and axial compression may be obtained using interaction formulae. In this procedure initial imperfection is taking into account through a compression load reduction factor, and the amplification of bending moments is approximated by means of interaction factors. This paper presents a comparative study of both procedures for cases where analytical second order solution is possible. Results show how interaction factors may underestimate member resistance in some cases, and how member slenderness affects differences in the resistance given by the two procedures. © 2007 Taylor & Francis Group.