Five principal viruses are recorded infecting cucurbit cros in Western Australia – cucumber mosaic virus, papaya ringspot virus, squash mosaic virus, watermelon mosaic virus, and zucchini mosaic virus. Of these the papaya mosaic virus, squash mosaic virus, and zucchini mosaic virus are widespread and cause significant yield loss and fruit quality defects in cucumber, honeydew melon, pumpkin, rockmelon, squash, watermelon, and zucchini crops. This fact sheet details about five main virus diseases affecting cucurbit crops – zucchini yellow mosaic virus, papaya ringspot virus, squash mosaic virus, watermelon mosaic virus, and cucumber mosaic virus – hosts, distribution, spread, symptoms, and control.