Three synthetic chemical compounds derived from thiosemicarbazones (4a, 4c , and 4g) were used to evaluate their antibacterial activities against Pseudomonas aeruginosa PN1 strains. Physiological, biochemical and molecular tests (16S rRNA) were performed to identify the strain PN1. Three methods for evaluating the bioactive activity of chemical molecules were applied: the diffusion method on MH agar, the microdilution method for determination of MIC and MBC, and the growth kinetics of indicator strains in the presence of chemical molecules. The results allowed us to conclude that molecules derived from thiosemicarbazones have varying effects against Pseudomonas aeruginosa PN1. Molecules 4c and 4g have an inhibitory effect (stationary or slowing bacterial growth) without being bactericidal, while molecule 4a showed a bactericidal effect (decreased bacterial growth). The MIC of molecule 4a was 62.5µg/ml , and the MBC was 125µg/ml. For molecules 4c , and 4g, the MIC was estimated at 125µg/ml and the MBC was greater than 125µg/ml. The tested compounds showed interesting and promising antibacterial properties.