A study was done to investigate the effects of supplementation of dry season grazing with Roselle seeds or groundnut seed cake on total voluntary dry matter intake, nutrient digestibility coefficients, total digestible nutrients, lambs live weight changes, body measurements and water consumption of Sudanese Desert sheep. The study was done at Abuzabad, El Nuhud District in West Kordofan State. Fifteen castrated lambs from Hamari sub-type of Sudan Desert sheep were sub-divided into three equal groups (5 lambs each). One group was offered natural grazing (NG), the second group was given natural grazing plus groundnut seed cake (NG+GNSC) and the third was fed on natural grazing plus Roselle seeds (NG+RS). Water was provided ad lib. The treatments lasted 77 days. Feed intake and water consumption were estimated daily while body measurements and body weight were taken weekly. Feed and faecal samples were taken for chemical analysis Statistical analysis indicated significant increase in total voluntary dry matter intake. It increased from 522g/day when lambs were fed on un-supplemented NG, to 810 and 845 g/day upon supplementation with GNSC and RS, respectively. The nutrients digestibility coefficients increased significantly (P<0.01) with supplementation, but no differences were observed in dry matter, organic matter and nitrogen free extract digestibility coefficients that could be attributed to type of supplement. Total digestible nutrients increased with supplementation (P<0.05) from 51 for NG to 56.9 and 61.5% upon supplementation with groundnut seed cake and Roselle seeds, respectively. Body weight increased from 20.10kg for lambs on NG to 24.50 and 25.70 kg upon supplementation with groundnut seed cake and Roselle seeds respectively. Feed conversion ratio improved from -22.32 for the animal groups on GN to 6.30 and 5.70 and daily growth rate from -27.50 when lambs left on GN only to 91.70 and 109.40 g/day upon supplementation with groundnut seed cake and Roselle seeds, respectively. Chest depth increased from 31.50 cm to 34.70 and 35.60 cm ; height at shoulder increased from 65.20cm to 68.00 cm and 69.00 cm ; and heart girth from 57.90cm to 64.70 cm and 66.50 cm upon supplementation with GNSC and Roselle seeds, respectively. No significant differences were observed in body length among the three groups. Water consumption increased from 1.126 to 1.476 L/day upon supplementation with GNSC and RS respectively. The study revealed that both supplements could improve nutritional status of the weaned lambs and that RS that are not usually used, could replace the cake in supplementation of lambs on NG during the dry season hence enabling producers and feedlot centers to reduce cost of production. Further studies are needed to evaluate effects of feeding lambs with Roselle seeds on meat quality.