This study was aimed at investigating the effects of biopriming with a number of native isolates of Trichoderma harzianum on the germination and seed vigor indices of a native cumin (Cuminum cyminum L.) population. Also, the effects of extracellular enzymes produced by these isolates as elicitors on the production and accumulation of secondary metabolites in the seedlings obtained from bioprimed seeds were studied. Based on the results, all the T. harzianum isolates were able to produce the enzymes amylase, protease, cellulase, xylanase, chitinase, and lipase. The results also showed that the cumin seed biopriming significantly affected the germination and seed vigor indices and improved the quality and health of seeds and seedlings. In this study, the essential oil of seedlings obtained from the bioprimed seeds was extracted by water distillation and its chemical compounds were identified by GC and GC/MS. The results showed that the main compounds identified included β-pinene, ρ-cymene, limonene, γ-terpinene, terpinen-4-ol, α-terpineol, cuminaldehyde, and β-farnesene. Also, T. harzianum and the enzymes secreted by it as elicitors increased the expression of genes associated with the production and accumulation of secondary metabolites in cumin. This is the first report on the effects of seed biopriming with the native isolates of T. harzianum on the essential oil compounds of cumin seedlings. The findings of this research showed that the amount of extracellular enzymes secreted by the T. harzianum isolates is different and affects the production and accumulation of secondary metabolites in cumin.