The aim of the present study was to evaluate inflammatory, oxidative, and nitrosative stress (IO&NS) blood markers as possible predictors of multiple sclerosis (MS) and its clinical forms. This study included 258 MS patients (175 with relapsing-remitting MS (RRMS) and 83 with progressive MS clinical forms) and 249 healthy individuals. Peripheral blood samples were obtained to determine serum levels of albumin, ferritin, C-reactive protein (CRP), total protein, lipid hydroperoxide by tert-butyl hydroperoxide-initiated chemiluminescence (CL-LOOH), carbonyl protein content, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter (TRAP). MS patients showed higher ferritin (p < 0.001) and CL-LOOH (p < 0.001) and lower albumin (p = 0.001), TRAP (p < 0.001), AOPP (p = 0.013), and NOx values (p < 0.001) than controls. Difference was not observed in CRP, total protein, and carbonyl proteins between patients and controls. In the logistic regression age-adjusted, ferritin and CL-LOOH showed positive association with MS and were predictors of MS development (OR: 1.006, 95 % CI: 1.003-1.009, p < 0.001 and OR: 1.029, 95 % CI: 1.007-1.052, p = 0.009, respectively). Albumin, TRAP, AOPP, and NOx were negatively associated with MS (p = 0.019, p = 0.003, p = 0.001, and p = 0.003, respectively). Moreover, other logistic regression age-adjusted showed that MS patients with progressive clinical forms had lower albumin and higher AOPP than those with RRMS (p = 0.037). In conclusion, ferritin, albumin, and biomarkers of IO&NS, such as CL-LOOH, AOPP, TRAP, and NOx were predictors of MS diagnosis, whereas albumin and AOPP were predictors that differentiated RRMS from the progressive clinical forms of MS.