Effect  of  different  modes  of  pollination, viz.,without  insect  pollination,  hand-pollination,  open-pollination and  open-pollination  +  hand-pollination  on  yield  parameters  of  4  summer  squash  (Cucurbita  pepoL.)  hybrids viz., Parikrama, Chandra, Chamatkar and Gold Queenwas studied at Research Farm of the Department of Entomology, CCS  Haryana  Agricultural  University,  Hisar  during  2014.  Irrespective  of  different  hybrids,  the  treatment  open-pollination  +  hand-pollination  and  open-pollination  produced  the  maximum  number  of  fruits  per  plant  (73.50  and 71.25%, respectively) followed by hand-pollination (59.08%) and no fruits were observed (0% fruit set) under without insect  pollination  treatment.  Average  fruit  weight,  fruit  polar  diameter  and  equatorial  diameter  were  maximum (135.30 g, 3.74 cm and 3.47 cm, respectively) under open-pollination + hand-pollination, while these were minimum (94.81 cm, 2.14cm and 2.48 cm, respectively) under hand-pollination treatment.  These results indicate that honey bees as well as wild pollinators are utmost essential for pollination of summer squash flowers and thus increasing fruit size and yield. Therefore pollinators conservation practices should be followed in summer squash growing ar-eas for getting higher yield and returns.