ABSTRACT: Some studies have characterized and evaluated the parasitic load of the Pacific sardine. However, there are few studies related to its physiology and parasites load. This study aimed to evaluate the blood parameters and the abundance of helminth parasites of sardines obtained from two samples from Todos Santos Bay during autumn 2013. The digenea Myosaccium ecaude parasite was the only species registered. Sardines had a prevalence of 28%, an average abundance of 25 and an intensity of 7 parasites. There were no statistically significant differences (P > 0.05) in most of the analyzed blood parameters (red blood cell count, hematocrit, leukocyte cellular differentiation, mean corpuscular volume, total protein, glucose, alanine aminotransferase, osmotic pressure, Na, K, and pH) of fish with and without parasites, except in white blood cell count and in Ca concentration that showed a marked decrease. The relationship between parasite abundance and blood parameters, based on the results of this study, it is not clear due to the low parasitic load.