Long melon [Cucumis melo var. utilissimus (Roxb.) Duthie & Fuller] cultivation in open field condition in northern India is hampered due to extremes of the temperature from September to January. Therefore, the present study was carried out to explore possibility for off-season production of long melon under protected conditions at Center for Protected Cultivation Technology (CPCT), ICAR-IARI, New Delhi in 2016–17 and 2017–18. Seedlings were transplanted as per five different spacing and branch pruning methods. The combination of closer spacing with maximum branch node pruning method under polyhouse structure was found better for off-season long melon production. Flowering appeared earlier by 4.02 days, first fruit picking by 5 days, additional number of pickings (5 times) and harvesting period extended by 60 days in polyhouse compared to insect proof net-house structure. The closer spacing S1 (50 cm × 20 cm) exhibited maximum weight of fruits, fruit yield, gross income as well as net-income and B: C ratio. Among pruning methods, complete branch pruning method P1 (single stem cultivation or branch less cultivation) contributed positively significant effect on all parameters of long melon. The combination of polyhouse structure with closer spacing (50 cm × 20 cm) and optimum branch pruning (after one node cutting) gave highest yield and net income per unit area for off-season cultivation of long melon.