Fusicoccum leaf blight, the most recent disease to affect rubber in Malaysia, is caused by a species of Fusicoccum, a fungus not known to cause rubber diseases elsewhere in the world. Since its discovery in 1987, when it affected a large stand of four-year-old trees, the disease has been observed at eight other locations spread over three different states in the country. Nursery, immature as well as mature plantings are affected. Incidence in the nurseries varied with the clone. High incidence was recorded on clones RRIM 901 and RRIM 905 but there was negligible occurrence on other clones. At the immature phase, the more severely affected clones were RRIM 937, PB 350, RRIM 901, RRIM 905 and BPM 24. In mature stands, disease incidence was rather low with few trees affected resulting in negligible defoliation and thus not affecting canopy density. Clone screening indicated that RRIM 937, PB 350, RRIM 600, RRIM 901 and RRIM 905 were the most susceptible. Highly resistant clones were PC 119, PR 261, PRR 255 and GT1. Attempts to eradicate the disease in source-bush nurseries and in three clone-trial areas did not prevent reappearance some months later. A recent attempt at chemical control on an immature planting had shown some promise.