Background: Pseudomonas aeruginosa (P. aeruginosa) is one of the most common causative bacteria in chronic wound infection. It is increasingly becoming resistant to many anti-pseudomonal agents. So, it is necessary to advance the field of alternative treatment. Probiotics are viable, non-pathogenic microorganisms that alter the micro-flora of the gastro intestinal tract of the host, yielding a positive influence on health and body physiology. Objective: To investigate the in-vitro effect exerted by Lactobacillus plantarum (L. plantarum) on the antibiotic sensitivity of P. aeruginosa. Methodology: This study was carried out in Medical Microbiology & Immunology Department, Faculty of Medicine, Tanta University on forty patients admitted, during the period of research (February 2017 to August 2017). P. aeruginosa isolates were identified by results of culture and conventional biochemical reactions. The effect of L.plantarum on antibiotic sensitivity of P. aeruginosa was detected by measuring the antibiotic sensitivity of the isolated strains of P. aeruginosa before and after addition of L.plantarum. Results: Among the forty wound samples investigated, the most predominant bacterial isolate was P. aeruginosa (50%). P. aeruginosa infection was more common in males than females with predominance in old age. P.aeruginosa susceptibility pattern to different antimicrobial agents significantly increased after addition of L. plantarum. 100% of isolates became sensitive to colistin sulphate followed by imipenem (70%), ciprofloxacin (65%), pipracillin–tazobactam (60%), gentamicin (35%), aztreonam (30%) and pipracillin (20%). Conclusion: P. aeruginosa was the predominant bacterial isolate in the studied wound infections. P. aeruginosa susceptibility pattern to different antimicrobial agents significantly increased after addition of L. plantarum.