Two experiments were carried out during the 2006/07 and 2007/08 winter seasons at El- Hammam area, Matrouh, Egypt to investigate the influences of supplemental irrigation (SI) and fertilization package (FP) under rainfed conditions on productivity of naked barley (Hordeum vulgare L.). Each experiment included 28 treatments which were; four amounts of supplemental irrigation (SI) i.e. SI₀): rainfed only; SI₁): 60 mm/ fad; SI₂): 90 mm/ fad and SI₃): 120 mm/ Fad. and seven fertilization packages (FP) treatments i.e. FP₀): without fertilization; FP₁): Bio-N; FP₂):  20 Kg N/ Fad.  + 7.5 Kg P₂ O₅/ Fad.  + 12 Kg K₂O/ Fad.; FP₃):  20 Kg N/ Fad.  + 7.5 Kg P₂ O₅/ Fad.  + 12 Kg K₂O/ Fad.  + Bio-N; FP₄): 40 Kg N/ Fad. + 15 Kg P₂O₅/ Fad. + 24 Kg K₂ O/ fad; FP₅): 40 Kg N/ Fad.  + 15 Kg P₂O₅/ Fad. + 24 Kg K₂O/ Fad.  +Bio-N; and FP₆): 80 Kg N/ Fad.  +30 Kg P₂O₅/ Fad.  + 48 Kg K₂O/ Fad.). Results showed significant differences among supplemental irrigation treatments in all the studied traits in both seasons. Also, results clearly showed that grain, straw and biological yields were increased by each increment in amount of water supply from 60 to 90 then to 120 mm/ Fad.  in the two seasons. It is evident that grain yield increased by 23.0, 82.7 and 111.1 % and by 22.9, 81.7 and 110.8 % in the first and the second seasons, respectively, due to increase of the added water supply amounts from 60 to 90 then to 120 mm/ Fad.  in respective order. Results indicated that FP₃  treatment application which included 20 Kg N + 7.5 Kg P₂O₅ + 12 Kg K₂O / Fad. + Bio-N gave the tallest plants, longest spikes, heaviest 1000-grain weight, as well as, the highest values of grain, straw and biological yields, as well as, water use efficiency compared to the other tried fertilization packages here in both seasons. It is evident that the positive response of naked barley plants was only to add 20, 7.5 and 12 Kg of N, P₂O₅ and K₂O/ Fad. in respective order, in addition to bio-N fertilizer as a package i.e. FP_3. Ultimately, to gain high productivity of naked barley economically, it could be adding SI by amount of 120 mm/ Fad. with applying FP i.e. 20 kg N/ Fad.  +7.5 kg P₂O₅/ Fad.  +12 kg K₂O + Bio-N/ Fad.  could be recommended under rainfed conditions at El-Hammam area, NWC of Egypt.