The purpose of the present study is to evaluate the antibacterial action of various extracts of Caralluma europaea, a Moroccan indigenous plant, on Rhodococcus equi, a known pathogenic bacterium affecting humans and animals. This gram-positive bacillus is largely known as a pulmonary pathogen in animals, mainly in foals, but affects also immunosuppressed persons, particularly AIDS patients. In this study, we tested three Caralluma europaea extracts (ethyl acetate extract, methanol extract and aqueous extract) of R. equi in a liquid medium and a solid medium as per the propagation method. Six antibiotics were then tested to compare their antibacterial action to that of the plant extracts. Results obtained with the solid medium showed that only the ethyl acetate extract resulted in bacterium growth inhibition. In fact, the average diameter of inhibition zones induced by ethyl acetate was 20mm. The six tested antibiotics showed a positive but different action with the exception of Kanamycin (KMN), which had no effect on this bacterium. The most effective antibiotic against this bacterium was Chloramphenicol (CHL) with an inhibition zone of 28.33mm. For Doxycycline (DOX), this zone was 26.33mm, close to that of ethyl acetate extract which was 20mm. For Amoxicillin (AMX), the inhibition zone was 10.33mm, for Cephalothin (KF) it was 9.66mm, and for Ampicillin (AMP) it was 8.33mm. Additionally, we measured the release of absorptive cellular content at 260 nm in the presence of ethyl acetate extract and of Chloramphenicol. We noted sudden mortality in the early hours of treatment. After 6 hours, we noted the release of 63% of cell contents in the case of ethyl acetate extract and 88% in the presence of Chloramphenicol. We also measured absorbance (DO) at 600 nm to evaluate growth inhibition in the liquid medium of Rhodococcus equi by ethyl acetate extract and by Chloramphenicol. The inhibition was complete after 3 hours for Chloramphenicol while for the ethyl acetate extract, it was observed after 5 hours of treatment.