The diseases in cucurbits occur during preharvest on the plants including fruits and postharvest stages on the fruits. The produce of crops may be contaminated in the field, but expression of symptoms may take place later. The infection caused by pathogens to commence diseases after harvest and its ultimate effect depends on various factors that can generally be related to the host, the pathogen and the environment. Heavy postharvest losses may occur due to susceptible cultivar to the disease, mishandling after harvest, inadequate packaging, temperature and relative humidity management and prolonged transport times. A significant loss of marketability of produce may take place in a short storage period (a few weeks) if proper postharvest measures have not been applied. A wide range of fungi and bacteria affect the postharvest losses and quality of produce. The pathogens infect the crops during fruit setting to after the harvest of fruits. The major postharvest diseases of Cucurbitaceae fruits are black rot or gummy stem blight, Phytophthora fruit rot, anthracnose, cottony leak, belly rot, Choanephora fruit rot, Fusarium rot, scab (gummosis), Rhizopus rot, blue mould rot, bacterial leaf spot, bacterial soft rot, etc. Important strategies for management of these diseases during preharvest and postharvest treatments include applying cultural practices, chemical methods, resistant cultivars and biological controls through botanicals and microbes and maintaining proper storage conditions to minimize postharvest losses and retain the quality of cucurbit fruits.