Testing effects of endocannabinoid anandamide on mouse behaviour on paired conflict social interactions we have found its inhibitory influence on aggressive activities in aggressive isolates and pro-aggressive effects in timid mice exhibiting on control interaction defensive-escape behaviour but no attacks. The aim of this study was to ascertain if the anandamide uptake inhibitor O-2093 can elicit similar behavioural changes on mouse agonist behaviour as anandamide as well as other cannabinoid receptor agonist previously tested (HU-210, methanandamide).In timid mice (n=11), all doses of O-2093 tested caused significant increase of aggressive behavioural acts (tail rattling, unrest, attack of the partner). We observed no changes in behaviour of aggressive mice. The present findings confirmed that inhibition of anandamide uptake is able to produce analogical pro-aggressive effects as administration of anandamide in mice showing on social conflict timidity. On the contrary, the suspected enhanced physiological effect of anandamide after administration of its uptake inhibitor was insufficient to produced reduction of aggressive activities in aggressive singly-housed mice measured earlier after exogenously given anadamide.