Objectives: To investigate the relation between vitamin D sufficiency (VDS) levels and outcomes of ICSI for infertile women Patients &Methods: 104 infertile women were clinically evaluated and given blood samples for estimation of serum levels of tumor necrosis factor-α (TNF-α) and 25-Hydroxy VD (25-OHVD) and were categorized according to VDS levels. All women underwent frozen embryo transfer after controlled ovarian stimulation. The chemical (CPR) and clinical pregnancy rates (CLPR), the early pregnancy loss (EPL), and the successful pregnancy rate (SPR) were evaluated concerning the estimated levels of 25-OHVD and TNF-α. Results: The CPR was 53.8% and was higher among VD deficient (VDD) women. The CLPR was 36.5% and showed an insignificant difference according to VDS status. The EPR was 20.2%, while the SPR was 16.3% and was significantly higher in VDS than in VDD women. There was a negative significant correlation between serum levels of 25-OHVD and TNF-α. The CPR and CLPR showed negative significant correlations with serum TNF-α levels. The SPR showed positive and negative significant correlations with serum levels of 25-OHVD and TNF-α, respectively. Conclusion: VD might improve ICSI outcomes through its modulatory action on the systemic inflammatory milieu. Pro-inflammatory cytokines had deleterious effects on ICSI outcomes and the balance between pre- and anti-inflammatory cytokines must be corrected before committing ART procedures