The interactions of gold nanoparticles (AuNPs) with human serum albumin (HSA) greatly influence their in vivo characteristics. It is important to develop conjugates that can serve as ideal structural models to understand the interaction of AuNPs with HSA. We report the synthesis and stabilization of AuNPs in HSA matrix with no additional ligands on the surface of the NPs. The hydrodynamic size of the AuNP–HSA conjugate is 22 nm, and transmission electron microscopy (TEM) measurement shows the core size as 8–13 nm. We have performed strip assay to establish that the biological activity of HSA is retained even after conjugation. Our cellular toxicity evaluation studies show that AuNP–HSA conjugates are nontoxic and biocompatible.