Antibiotic resistance has been increasing drastically over the years despite the efforts to lobby against unnecessary use of antibiotics. The ability of cells to form drug resistant biofilms, a complex architecture of cells encased in an extracellular polymeric matrix, is one of the many reasons for the failure of antibacterial treatment. A classic example is the opportunistic pathogen Pseudomonas aeruginosa which forms biofilms on medical devices and living tissues, which is intrinsically resistant against a wide range of antibiotics. P. aeruginosa release virulence factors such as pyocyanin (PCY), pyochelin (PCH), pyoverdine (pvdE) and elastase (LasB) which contributes to tissue damage. We previously showed that olive leaf extract has antimicrobial activity against Gram-positive organisms. The important secoiridoids found in olive leaf such as oleuropein, hydroxytyrosol and verbascoside could play a role in the anti-microbial activity of olive leaf extracts. Therefore, this study aimed to examine the effect of olive leaf extracts and combinations of its purified components on planktonic cell growth, biofilm formation and excretion of extracellular virulence factors of P. aeruginosa. The effect of the extracts and purified compounds on bacterial motility, which is an indication of virulence, was also investigated. The extracts were shown to have limited anti-microbial activity against this Gram-negative bacterium. The effects of olive leaf extracts, oleuropein, hydroxytyrosol and verbasocide on biofilm formation and virulence are also reported.