Toxoplasma gondii is an intracellular parasite ruthless capable to colonize many types of cells of vertebrate animals. The penetration of the host cell is an active process driven by the parasite. This process is directly linked to the release of proteins contained in the secretory organelles: micronemes, roptrach and high density granules. Microneme proteins responsible for adhesion of T. gondii host cell, a protein involved in the production of roptrów parasitophorous vacuole. Granule proteins and high density are secreted continuously during the intracellular development of the parasite and its access to nutrients and replication. In this paper presents the current state of knowledge on the secretory organelles of T. gondii and their role in the process of penetration and colonization of host cells.