Garlic (Allium sativum L.) is one of the horticultural commodities of high economic value in Indonesia where Province of West Nusa Tenggara (NTB) is one of the largest garlic-producing areas. One of the main constraints facing by farmers during postharvest storage is seed-borne fungal contaminants. This study aims to investigate fungal contaminants on garlic seeds in the Sembalun Highlands (1200 m above sea level) of East Lombok Regency, West Nusa Tenggara (NTB) Province of Indonesia. Research was conducted in September–November 2018 using Blotter on Test method. Garlic seed samples (Sangga Sembalun variety) were collected from farmers garlic storages in Sembalun Highlands. Preparation of garlic samples, incubation, and observation were conducted at the Biology Laboratory, Faculty of Mathematics and Natural Sciences, Mataram University. Identification was conducted based on Barnett and Hunter (1998) and data percentage of infection were recorded. Results show that there were two main seed-borne fungal contaminants isolated from garlic seed samples, namely Aspergillus sp. and Fusarium oxysporum. The genus of Aspergillus belongs to the Ascomycetes class. It can be found everywhere in nature and grows as a saprophyte in decaying plants. While F. oxysporum is a plant pathogenic fungus on garlic worldwide that often infects seeds from the nursery period to cause wilting symptoms in plants. This causes crop yields to decrease, resulting in a decrease in production. For further research, the fungi isolated should be identified at the species level using molecular characterization. For farmers, seed treatments are required to anticipate and reduce the impact of these contaminants on garlic production.