Fresh and partially processed fish are subject to spoilage either by microbes or by fat oxidation, which gives a great attention to fish preservatives, especially natural preservatives, a great interest as alternatives to chemical preservatives. In this study, thyme extract has been used along with smoking and soaking fish fillets in brine solutions as an alternative method of preservation. Fish fillet samples were evaluated for their chemical composition (moisture, pH and protein contents), total bacterial count, and the numbers of isolated Salmonella spp., Escherichia coli, S. aureus, and Pseudomonas spp. The obtained results showed a decrease in pH values and moisture contents and an increase in protein contents in smoked fish fillet soaked in brine solution alone without thyme extract or with the addition of thyme extract. The thyme extract showed a high reduction rate in Salmonella spp., E-coli and Pseudomonas spp numbers in comparison with the control and the fish fillet samples soaked in brine solution. On the other hand, S. aureus showed high resistance rate. The results indicated that, thyme could be added to the brine solution used for the preparation of smoked fish as an antimicrobial agent.