Gold nanoparticles are attracting increasing attention in nanomedicine due to their inherently low toxicity and unique optical properties. In particular, gold nanorods have been used in the thermal therapy due to their tunable strong longitudinal plasmon resonance in the near infra-red region and high conversion efficiency from optical to thermal energy. In this study we explore the potential of gold nanorods for photoacoustic image-guided photothermal therapy to treat cancers. We synthesize the gold nanorods and make them biocompatible by replacing the cytotoxic surfactant used in the synthesis (cetyl trimethyl ammonium bromide) with a biocompatible molecule and then demonstrate the targeting to the cancer cells by bioconjugation of the modified nanorods.