This study aimed to evaluate effect of replacing soybean meal with Moringa Seed Cake (MSC) on degradation of dry matter (DM) and fiber as well as methane production using in vitro fermentation technique. Basal diet consisted of Egyptian clover hay and concentrate (1:1). MSC was used to replace 0, 5, 7.5, 10 and 12.5% of soybean meal on total DM basis. Dry matter, neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined before and after 48 h of fermentation. Hemicellulose (hemi), cellulose and degradation of DM, NDF, ADF and hemi (dDM, dNDF, dADF, dhemi) in incubated samples were calculated. Total gas production (TGP) and methane production were measured at different intervals. Use of 5% MSC did not reduce DM degradation as compared to control. Total gas production only differed between MSC levels when expressed per gram ADF at 12 and 36 h, while all other measures of TGP (TGP per unit of degraded DM and fiber fractions) and methane did not differ between 5% MSC and control. The 12.5% MSC ration resulted in decreased TGP per unit DM and fiber fractions from 6 to 48 h of incubation compared to control. Total gas production decreased with increasing ADF and NDF and increased with increasing dNDF, but was unaffected by dADF, at any MSC level. The 12.5% MSC significantly reduced methane to a substantially (>80%). The results show that 5% MSC can be used in ruminant diets without negative effects on fiber degradation, rumen fermentation or methane production.