The experiment was conducted at Agronomy research field of Sher-e-Bangla Agricultural University, Dhaka, during 10 November 2012to 10 March 2013 to observe the response of seedling tuber weight and plant spacing on performance of potato. Four weight of seedling tubers viz., 40 ± 2, 30 ± 2, 20 ± 2 and 10 ± 2 g and three plant spacing viz., 60 cm × 25 cm, 60 cm × 20 cm and 60 cm × 15 cm were used as treatment and laid out in Randomized Complete Block Design (RCBD)with three replications. Results revealed that, plant height, stems hill-1,and Leaf Area Index, Total Dry Matter plant-1 and Total Dry Matter m-2 and Crop Growth Rate increased with increasing seedling tuber weight. The highest tuber yield ha-1 both gross and marketable was recorded in the tuber weight of 30 ± 2 g and the lowest from smaller seed tuber of 10 ± 2 g. The highest number of stems and leaves hill-1, LAI, TDM plant-1, tubers hill-1, single tuber weight, tuber weight hill-1, gross and marketable tuber yield ha -1were observed in the wider spacing of 60 cm × 25 cm and the lowest from closer spacing of 60 cm × 15 cm. However, combindly the highest gross and marketable tuber yield was observed in the treatment combination of 40 ± 2 g seed tuber with the plant spacing of 60 cm × 25 cm. But economic point of view, the seedling tuber weight of 30 ± 2 g with plant spacing of 60 cm × 20 cm was more profitable than those of other treatment combinations.