Long-gauge fiber Bragg grating (FBG) strain response is characterized by sensitivity to local damage and obtaining global behavior (e.g., deflection, natural frequency) of structures, and can be measured with high-accuracy and high sampling frequency. Recent research about performance assessment of engineering structures using long-gauge FBG sensors is reviewed in this paper. Firstly, description of long-gauge FBG sensing technique is presented. Secondly, assessment methods of structural local behavior using long-gauge strain response are classified into two types (time domain-based and frequency domain-based method). Time domain-based methods are those methods which directly use long-gauge strain to identify local damage of structures. Frequency domain-based methods are those methods which extract frequency features (e.g., modal macro-strain) of structures for damage identification. Thirdly, assessment methods of structural global behavior using long-gauge strain response are summarized. These methods include calculating deflection of structures from long-gauge strain response, extraction of natural frequency from dynamic strain time-history, and calculating displacement mode shape from modal macro-strain. Finally, suggestions on the selection of methods for performance assessment of engineering structures are proposed and some challenges are discussed.