This study suggested growing faba beans in the watermelon cultivated area by relay intercropped melon with faba bean to reduce the faba bean production-consumption gap, maximize the productivity per unit area, reduce the use of nitrogen fertilizer and increase the income of farms. So, A field experiment was implemented during 2020/2021 and 2021/2022 seasons at Ismailia Experiment Station, ARC, Ismailia Governorate, Egypt, to study the effect of plant spacing (50, 75 and 100 cm) and N fertilization levels (40, 60 and 80 kg/fad) of watermelon relay intercropping with faba bean on yield for both crops, land equivalent ratio (LER), and profitability per unit area. A split-plot design was used with three replications. Plant spacing of watermelon were assigned in main plots and N fertilization levels were arranged in sub-plots. Results indicated that growth, yield and its attributes of faba bean were insignificant effect by watermelon plant spacing and N fertilization levels of watermelon as well as their interaction. Contrary, plant spacing and N fertilization of watermelon relayed with faba bean significantly affected watermelon traits. Where, increasing plant spacing from 50 to 100 cm between hills with applied 80 kg N/fad significantly increased branch length, number of branches/plant, number of fruit and mean fruit weight. However, the highest fruit yield (25.2 ton/fad as average of both seasons) produced by planting watermelon spacing at 75cm with applied 80 kg N/fad, but without significant differences with 60 kg/fad. Therefore, intercropping watermelon at plant spacing 75cm with applied 60 or 80 kg N/fad had the highest LER 1.75, ATER 1.05 and the highest in both seasons. While, the highest net return 25511 L.E/fad was achieved with 60 kg N/fad and at par with the net return 25502 L.E/fad by 80 kg N/fad. In conclusion, relay intercropping watermelon with faba bean at 75 cm plant spacing with applied 60kg N/fad produced 24.9 ton/fad fruits of watermelon plus 8.3 ardab/fad of seed faba bean and increased net return by 80.2%, as well as saved land by 75% and N fertilizer by 25% compared to sole watermelon culture, as average of both seasons.