Microbial contamination of cough syrups can bring clinical hazards as well as physical changes in the product. The objective of the current investigation was to assess and compare the ability of imported and locally manufactured cough syrups to maintain minimum or no microbial growth after being challenged with different types of microbes. The growth of five microorganisms of known quanta of S. aureus, E. coli, P. aeruginosa and C. albicans was compared among five different cough products designated A through E. Two of the products (A and E) were locally manufactured while three (B, C and D) were imported products which contained different preservatives. Both A and E did not indicate the type of preservative used. Normal saline was used as a positive growth control. Growth of microorganisms into syrups was compared by counting the colony forming units (CFUs) from a subculture of inoculated syrups at zero, 3, 6, 24 and 48 hr intervals. 1) at time zero, growth of S. aureus was seen in all products except product B; 2) little or no growth of C. albicans, P. aeroginosa and E. coli was observed at time zero; 3) no growth of any of the tested microbes was seen when subcultures were done after 6 hours of inoculation; and 4) imported products showed lesser or no microbial growth compared to locally manufactured ones. Normal saline showed heavy growth of all tested microbes while unchallenged syrupsof the tested products showed no signs of microbial growth at all tested times.Despite the noticeable growth of S. aureus at time zero, all tested cough syrups passed the pharmacopeal guidelines regarding microbial challenge. Good manufacturing and packaging practices need to be implemented and maintained by local pharmaceutical companies. The Palestinian general public needs to be educated on the proper handling and storage of oral liquid pharmaceuticals to eliminate or reduce microbial contamination.