Disease caused by Phytophthora spp in rubber tree (Hevea brasiliensis) is one of the major factors leading to reduction in the yield of natural rubber (NR), and use of resistant clones is one of the most sustainable ways of managing it. A reliable screening methodology is important for assessing the resistance levels in a breeding population, and assessment of the resistance levels of the existing Wickham clones, is an important prerequisite in breeding for resistance to the disease. A knowledge of the resistance levels of the clones is important to identify potential sources of resistance in the elite germplasm, as well as identify resistant and susceptible clones to be used as checks. The present study was therefore undertaken to optimise the in vitro screening protocol and to evaluate resistance reaction of Wickham clones of Hevea to P. meadii infection in an effort to identify clones that could be used for disease resistance breeding. An in vitro protocol for efficient zoospore production of P. meadii was optimized, which generated large quantities of zoospores, essential for screening of rubber clones for Phytophthora disease resistance. One hundred H. brasiliensis clones along with H. benthamiana and an interspecific hybrid FX 516 (maintained at the clone museum of Rubber Research Institute of India) were screened by artificial zoospore inoculation with P. meadii on detached leaf discs maintained in moist chamber. The size of lesion procuded on the leaf following challenge inoculation was inversely proportional to the resistance level of the clone towards P. meadii infection. Based on the level of resistance, the clones were clustered into five categories. Clones with extreme level of resistance and susceptibility were identified along with the majority of the Wickham clones showing moderate levels. The H. brasiliensis clones RRIM 608 and RRII 15, along with H. benthamiana adn FX 516, were found to be highly resistant, whereas RRIM 600, RRIM 603, RRIM 611, RRIM 621, RRII 16 and RRII 30 were highly susceptible to P. meadii infection.