Sorghum (Sorghum bicolor l.) is the main crop, and mung bean is the supplementary crop in the sorghum-mung bean intercropping system commonly practiced in the semi-arid region of Wag Hemira Zone, Ethiopia. However, the optimal row arrangement and seed proportions for this intercropping system have not been thoroughly investigated. Therefore, this experiment was conducted in 2023 at the Aybra main research site in the semi-arid area of Wag Hemira Zone, Ethiopia, to determine the optimum level of mung bean seed proportion and the proper sorghummung bean row configuration to achieve maximum productivity of the component crops and profitability of the overall sorghum-mung bean additive series intercropping system. A 3 x 4 factorial arrangement in RCBD design consisting of fourteen treatments including sole sorghum and mung bean as a check. The treatments consists of three seed proportions (%) of mung bean from the recommended practice (200%, 100%, and 67%) and four sorghum (S)-mung bean (M) row configurations (ratios) (1S:1M, 2S:1M, 1S:2M and 3S:1M) . Data on the agronomic attributes of the component crops in a mixture were collected in the field. Land equivalent ratio (LER), Area time equivalent ratio (ATER), monetary advantage index (MAI), competitive ratio (CR), and partial budget analysis were also calculated. These Data were analysed using SAS software. Most of the of agronomic attributes of the component crops in sorghum - mung bean intercropping were significantly (P<0.05) affected by row configuration and seed proportion of mung bean and by their interaction. The highest grain yield of sorghum (3112.3 kg ha ) was found when 67% seed rate of mung bean was planted in 1S:1M row ratio. The highest seed yield of mung bean (724.94 kg ha -1 ) was found when 67% seed rate of mung bean was planted in 1S:2M row ratio. The highest total LER (1.39), ATER (1.28) and MAI (57119,ETB ha ) were found when 67% seed rate of mung bean was planted in 1S:1M row ratio. The highest net benefit (207537.9 Birr ha -1 ) with acceptable range of marginal rate of return (2094.203) was obtained when 200% seed rate of mung bean was planted in 1S:1M row ratio. Thus, based on economic benefit, intercropping of sorghum with mung bean in one to one row ratio with 67% 200% seed proportions of mung bean could be recommended for the study area. But for reliable results and recommendation, it is advisable to repeat the experiment at least for one more season over various locations. -1 -1