Abstract. Yulia E, Mahmudah AI, Rahayu A, Nasahi C, Maharani Y, Suganda T, Widayat D. 2022. Phytopathogenic fungi as potential biocontrol agents against an invasive weed, Asystasia gangetica, at Sakambangan rubber plantation in Garut, West Java, Indonesia. Biodiversitas 23: 4532-4538. Many weeds are invasive species causing both economic and ecological losses. Asystasia gangetica is one of invasive species from the Acanthaceae family and has now been established as one of the most important weeds of rubber plantation. Mechanical control of A. gangetica is ineffective, while chemical control is harmful to the environment. Thus, it is imperative to explore alternative control methods. This study aimed to carry out an inventory of pathogenic fungi isolated from A. gangetica and test their pathogenicity to A. gangetica and rubber seedlings. This research was conducted from November 2021 to February 2022. The methods used were field observation and laboratory test conducted at the Sakambangan rubber plantation, Garut District, West Java and the Phytopathology Laboratory, Department of Plant Pests and Diseases, Faculty of Agriculture, Universitas Padjadjaran. Pathogenicity test was carried out using water-culture method to grow the tested plants without soil. Fungi isolated from A. gangetica identified as Fusarium sp., Pestalotiopsis sp., Colletotrichum sp. and Cercospora sp. were tested to be pathogenic to A. gangetica, and deemed potential biocontrol agents. However, Pestalotiopsis sp. and Cercospora sp. were also pathogenic to rubber seedlings which make them ineligible as biocontrol agents for A. gangetica in rubber plantations.