Near infra-red (NIR) fluorescence imaging offers high sensitivity and specificity for cancer detection and tumor margin localization. In this paper, a compact and wearable NIR fluorescence imaging system (FIS) for image guided surgery is presented. The proposed FIS captures 27 frames per second of both NIR and visible spectrum data, allowing for minimum detection of 10nM of ICG concentration. The design tradeoffs of the complete system are carefully analyzed. The performance of the proposed FIS is evaluated under both sensitivity test and experimental mouse study. The imaging system is currently used in clinical trials for imaging sentinel lymph nodes in breast cancer and melanoma patients.