An experiment was conducted at the research field of the Horticulture Research Center at Labukhali, Patuakhali during the period from January to March 2014 to find out the most suitable BARI mungbean variety and optimum rates of N concerning higher seed yield under the regional condition of Patuakhali (AEZ–13). Two BARI mungbean varieties namely BARI mung–5 (V₁) and BARI mung–6 (V₂) and five levels of N fertilizer including control viz. 0 kg N ha^–1 (N₀), 30 kg N ha^–1 (N₃₀), 45 kg N ha^–1 (N₄₅), 60 kg N ha^–1 (N₆₀), and 75 kg N ha^–1 (N₇₅) were used for the present study as level factor A and B, respectively. In case of variety, BARI mung–6 produced significantly longest pod (7.56 cm), maximum pods (9.14) plant^–1, maximum seeds (9.14) pod^–1, higher weight of 100–seed (4.48 g), highest seed weight (4.33 g plant^–1) and highest seed yield (1.56 t ha^–1) than BARI mung–5 at harvest. In case of N fertilizer, longest pod (7.96 cm), maximum pods plant^–1 (10.45), maximum seeds pod^–1 (9.70), higher weight of 100–seed (4.52 g), higher weight of seed (5.73 g plant^–1) and greater seed yield (1.85 t ha^–1) were also obtained in 45 kg N ha^–1 compare other N levels. The BARI mung–6 × 45 kg N ha^–1 for seed yield was found under the regional condition of Patuakhali (AEZ-13).