Background: Sirtuin-1 (SIRT1) may affect multiple sclerosis (MS) disease. This study aimed to investigate the level of serum SIRT1, mRNA expression and genetic polymorphisms in Egyptian MS sufferers. Also, to assess its role as a possible biomarker in predicting the risk of MS and to evaluate the association between its levels and disability of MS. Measurement of SIRT1, serum level, mRNA expression level and genotyping for sirtuin-1 gene polymorphisms in 240 Egyptian subjects; 120 MS sufferers and 120 healthy control subjects. Results: There was a significant diminishment of level of serum sirtuin-1, and sirtuin-1 mRNA expression in MS sufferers compared to control subjects. Different sirtuin-1 single nucleotide polymorphism frequencies were statistically significant in MS sufferers compared to the control subjects. Moreover, a negative correlation of serum level of sirtuin-1 in MS sufferers with MS disease duration, disability according to Expanded Disability Status Scale (EDSS) score, cholesterol, and triglyceride serum levels. Regarding the sirtuin-1 gene polymorphisms in MS sufferers, the rs7895833 GG genotype had significant higher cholesterol, and low-density lipoprotein (LDL) levels than the GA and AA genotypes and that the rs7069102 GG genotype had a higher LDL level than the CG and CC genotypes while the rs2273773 TT genotype was significantly associated with cholesterol, and LDL levels than the TC and CC genotypes. No significant difference was detected in EDSS score comparing different sirtuin-1 genotypes among MS sufferers. In MS sufferers, rs7895833 G allele can be independently associated with cholesterol, triglycerides, and LDL levels. rs7069102 C allele can be independently associated with LDL level. With regard to rs2273773, T allele, it can be independently associated with cholesterol and LDL levels. Conclusion: There was a significant association between different sirtuin-1 gene polymorphisms and dyslipidemia which may modulate the course of MS disease. Furthermore, serum sirtuin-1 level can be considered as a possible predictor of disability in multiple sclerosis sufferers.