With Lying and deception show up as a behaviour in humans and animals respectively. For both species this behaviour brings important social consequences. Today, it is well known that all behaviours are structured on body-neural system/brain-environment totality. All living beings have a nervous system/brain shaped according to their evolutional properties. This nervous system/brain form a cognitive-affectional-behavioural background and a species-specific identity. It is observed that deceptive behaviours in animals contain -in additon to those programmed biologicallly- some named as “tactical deception also noted in humans as manipulative deception . Manipulative tactical deception requires -in addition to some other cognitive-affective abilities- a Theory of Mind, which existence in animals is disputable. Tactical deception is accepted as an evidence for the existence Theory of Mind in animals by some researchers. In this study it is aimed to evaluate lying and deception behaviours in humans and animals based upon some scientific findings of various disciplines such as evolutionary biology, comparative cognition, ethology and neuroscience by adopting a comparative viewpoint and to establish some inferences about the relation of consciousness-behaviour for both species.