Objective: Roquinimex is a drug with effects on inflammation and tumors. The pharmacological effect is not fully understood, and the molecular mechanism most characterized in vitro is an increase of plasminogen activator inhibitor type 2 (PAI-2) in human peripheral blood monocytes. The aims were to investigate peripheral pharmacological effects of roquinimex on peripheral blood monocytes and dog gingival fluid (GCF).___TAGSTART___BR___TAGEND___ Design: Six dogs were used in a cross-over study. The amount of GCF was determined with a Periotron®. The PAI-2 concentration in GCF was determined with ELISA. Monocytes were isolated from peripheral blood.___TAGSTART___BR___TAGEND___ Results: Dogs treated with the drug had significantly lower GCF flow values and the PAI-2 concentration in GCF was higher, but no effect was seen on peripheral monocytes.___TAGSTART___BR___TAGEND___ Conclusion: Roquinimex treatment led to a consistently decreased flow rate of GCF and a higher local concentration of PAI-2 in GCF.