Eucalyptus pellita is species including of family Myrtaceae. This species is one of the priorities for industrial timber estates because it is easy to adjust and the wood can be used as raw material for pulp and paper. This study aimed at determining the symptoms and sign of diseases on shoot, stem and root, the causal agent as well as the incidence and severity of disease. The study was conducted at PT Surya Hutani Jaya, Sebulu in Kutai Regency, East Kalimantan Province and continued with the identification of pathogen in Laboratory of Forest Protection, Faculty of Forestry, University of Mulawarman. The object of the study was E. pellita progeny test of 6 years old, and at the nursery. The seed was originated from the clone of Riau (Sumatera). The study revealed that there was a dieback disease caused by Botryosphaeria sp., stem canker by Coryneum sp., root rot by Ganoderma sp. and termite Coptotermes sp. at the plantation, while at the nursery was found damping off caused by Fusarium sp., leaf feeders of locust Atractomorpha crenulata and leaf roller caused by caterpillar Strepsicrates sp. The incidence of dieback disease at plantation ranged from 79.2% to 6.3%, stem canker was only one tree (47%), root rot was also only one tree (46.8%), and termite attack ranged from 70.8% to 39.6%. The severity of dieback disease at plantation ranged from 22.2% to 4.2%, stem canker 1.4%, root rot 2.8%, and termite attack ranged from 4.2% to 1.4%.