The rootstock potential of Turkish Lagenaria siceraria germplasm for watermelon was evaluated. Among 210 accessions, 72 genotypes were selected based on morphological characteristics. Two commercial hybrid rootstocks were also used for comparison. Crimson Tide watermelon cultivar was used as a scion. Emergence rate, hypocotyl morphology, survival rate, and resistance to Fusarium oxvsporurn f. sp. niveum (FON) were investigated. Grafted plants were grown for 3 weeks in order to investigate the effect of rootstocks on plant growth. Leaf number, shoot dry weight, and root dry weight were determined. Emergence rate was ranked between 72% and 100% in collected genotypes. The highest graft compatibility was 99% while the lowest graft compatibility was 70%. All the grafted plants showed better performance than control plants regarding plant growth. All bottle gourd genotypes were tested against known 3 races of FON and all of them showed resistance against it. However, 9 genotypes showed yellowing but reisolation from those plants showed that yellowing was not due to FON. Crimson Sweet watermelon cv. susceptible to 3 races of FON was grafted onto 10 Lagenaria siceraria genotypes with the highest graft compatibility with watermelon. While all grafted plants showed resistance to FON, ungrafted Crimson Sweet watermelon cv. was found susceptible to 3 races of FON. The results showed that Turkish L. siceraria germplasm has powerful rootstock potential for watermelon against Fusarium wilt and it is a good resource for rootstock breeding programs.