Abstract: In this study, the effect of different rootstocks on watermelon plant growth, fruit yield and quality were studied by comparing grafted plants with non-grafted ones under low tunnels for early production and later open field growing conditions. The watermelon (Citrullus lanatus (Thunb.) Matsum and Nakai) cultivar Crispy was grafted onto TZ-148 and RS-841, commercial hybrids of C. maxima x C. moschata and an experimental rootstock (Lagenaria siceraria) cv. 64-18. Non-grafted plants were used as control. Grafting significantly affected plant growth. Control plants had short main stem, less number of lateral vine and low root dry weight. Fruit yield was positively influenced by grafting when compered with the control under two growing conditions. There was a difference among grafted plants, 64-18 was significantly poor for yield characteristics than the other rootstocks. Detrimental effects were not determinated in fruit quality such as fruit index, rind thickness and soluble solid contents on grafted plants. These results showed that the use of grafting can be an advantageous alternative in watermelon production. Grafted plants improved plant growth and yield without any harmful effects on fruit quality. The positive effects of grafting can change according to the rootstock being used.