Background Multiple sclerosis (MS) is a disabling immune-mediated disease of the central nervous system. Ministry of Health and Population’s statistics show that MS comprise 1.4% of all neurological diseases, putting into consideration, current economic crisis; it is needed to predict disease severity with an acceptable cost-efective method. Complete blood count (CBC) parameters are supposed to be cheap, and simple markers for the systemic infammatory state. This study aims at evaluating role of neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) in predicting the severity of MS. Therefore, this retrospective cohort study was done on 150 MS patients attending MS clinic during year 2022. All patients were subjected to complete medical history. Estimation of the disability was done through the extended disability status scale (EDSS) and analysis of diferent parameters of baseline CBC before starting therapy. Results A cutof value of NLR≥2.95 and PLR≥201.5 could predict prognosis of MS. Risk factors of sever MS are high NLR, PLR, high body mass index and absence of disease-modifying therapy. Conclusions Neutrophil/lymphocyte ratio and platelet/lymphocyte ratio are cheap valid useful predictors of increased relapse rate and severity in MS. Highlighting the role of both ratios at time of frst diagnosis helps physicians to predict prognosis of patients in context of severity. Paying special attention to those with higher ratios can lead to improve patient outcome and reducing disease burden.