Toxoplasma gondii is ubiquitous obligate intracellular parasite and is one of the most important pathogen for humans and animals. In humans, T. gondii has two life forms: tachyzoites and bradyzoites. Tachyzoites form of T. gondii can cause acute infection, and it is called toxoplasmosis. The development of latent bradyzoites from rapidly growing tachyzoites has been linked to cellular and environmental stresses which are associated with heat shock proteins (Hsps). Hsps play a protective role against stressors. Hsp40 is an important member of Hsp family and T. gondii has 36 predicted Hsp40 family members. Therefore, we studied the cloning and biochemical characterization of the T. gondii RH strain Hsp40 protein-Gok1. Hsp40 prevents protein aggregation and induce refolding. Consequently, Hsp40s may play essential roles in the mechanisms of bradyzoite development and survival in the host organism. Hsp40-Gok1 functional and structural properties may facilitate drug design and protein targeting against toxoplasmosis.