Ticks are significant bloodsucking ectoparasites. Apart from causing blood loss and host skin damage, ticks are important vectors of tick-borne pathogens that cause disease in humans and animals as well as significant economic loss. For biological success, ticks evolved these substances with immunomodulatory activities capable of inhibiting host defence reactions (haemostasis, inflammation and immunity reactions), and which have a radical significance for their survival. The resulting feeding site represents a favourable environment and many pathogens began exploiting ticks to facilitate their transmission to the host. The structural-functional relationships of some salivary compounds have been outlined; however research on tick sialomas indicates that further extensive exploration is required on the subject. Also, tick saliva is a complex pharmacological component with great therapeutic potential for the treatment for some diseases.