The nutmeg plant (Myristica fragrans houtt) is a native plant of Maluku Province, Indonesia, which has historical and economic value and is also an important export commodity. The decline in nutmeg productivity in Aceh Province was due to dieback disease caused by the pathogenic fungus Lasiodiplodia theobromae. Currently control with antagonistic agents has been widely developed, one of them is with Talaromyces pinophilus. The purpose of this study was to determine the effectiveness of the dose of Talaromyces pinophilus in controlling dieback disease on nutmeg seedlings. The design used was a non-factorial completely randomized design with six treatments and four replications. The variables observed in this study were incubation period, disease incidence, and length of xylem discoloration. The results showed that T. pinophilus 30 g could significantly prolong the incubation period of L. theobromae, which was 68.65 days, reduced the incidence of disease by 20% and the length of the lesion formed was 0.73 cm.