Alternaria leaf significant blight is an important disease of sunflowers in India and elsewhere, causing significant yield losses during rainy seasons. Twenty-three moderately resistant genotypes, along with 6 interspecific lines derived from Helianthus tuberosus, were evaluated under natural epiphytotic conditions. The highly susceptible line L-101 was planted along all the borders and in between as an infector and spreader of the disease. The disease severity was assessed using 0-9 numerical rating system based on the infected area of plants during the beginning of anthesis and at full maturity of crop growth. None of the genotypes tested, including interspecific lines, recorded high levels of resistance. Most of the genotypes tested were highly susceptible. Three germplasm lines, viz., 180, 873, 1229, and the hybrid ISFH-306, recorded moderate levels of resistance. The results indicate that a high level of resistance is not available in the limited cultivated germoplasm tested. An alternate strategy to utilize the available low levels of resistance to develop resistant populations is discussed.