Structural systems are prone to global as well as member imperfections in geometry. These imperfections should be accounted for when considering structural stability and strength requirements of both sway and non-sway frames. In this thesis work, stability of equilibrium of imperfect systems is examined since it is an instability issue. Code provisions for imperfection are assessed. To evaluate strength requirements of imperfect structural systems, the imperfection effects are quantified in terms of an initial sway imperfection.The significance in analysis result is examined by carrying out frame analysis. This work could benefit structural engineering professionals and students by providing a detailed overview of the issue. It can also help to evaluate existing practices with regard to imperfection.