Bacterial endometritis is the major cause of mare infertility. This study was carried out to investigate the efficiency of using alternative ways of treatment for endometritis by using selected antibiotics or platelet-rich plasma (PRP) or combinations between them. Of a total of 46 mares, 39 suffered from endometritis (G1) and 7 were fertile mares (G2). The most commonly isolated bacterial species were E. coli (12 isolates, 30.77%) S. aureus (9 isolates, 23.07%), K. pneumoniae (8 isolates, 20.51%) followed by Strept. equi (7 isolates, 17.95) as single infection and Strept.equi+ E.coli+ K. pneumoniathen (3 isolates, 7.7%) as mixed infection .All isolates were susceptible to the widely used Amikacin and Gentamicin. Before the beginning of treatment, (G1) was subdivided into three groups: 13 mares treated with a selected antibiotic (G3), 13 mares treated with PRP (G4), and 13 mares treated with a combination of antibiotics and PRP (G5). Our study recorded a significant increase in nitric oxide (NO), haptoglobin (HB), and malondialdehyde ( MDA) levels in (G1) compared with (G2), with a significant decrease in total antioxidant (TAC). We found that the most effective result was detected in G5, which recorded a marked decrease in bacteria isolates, a significant decrease in NO, HB, polymorphonuclear neutrophils (PMN) and MDA levels. In addition to increasing the conception rate (92.3%) compared with other groups, we concluded that using selected antibiotics with PRP in the treatment of endometritis was effective in decreasing uterine infection and have a great role in improving the immunological status and elevating the conception rate.