In this study a combined composting-vermicomposting process with Eisenia fetida was investigated for pistachio waste (PW) treatment mixed with cow dung (CD) in different ratio (100% CD (T₁), 25% PW (T₂), 50% PW (T₃), 75% PW (T₄), and 100% PW (T₅)) as a substrate in experimental scale. The process was performed in two stages, including pre-composting, and vermicomposting which operate in 45d for each stage in the pilot scale. Physico-chemical parameters and worm growth ratio in different treatments were measured and compared. The results showed that the combined process significantly increased the quality of final product and the produced fertilizer was homogeneous, granular, odorless, and nutrient rich. Physico-chemical analysis showed a significant reduction in the C:N ratio (41.13% in T₂ to 69.14% in T₅), total organic carbon (TOC) (12.26% in T₂ to 37.06% in T₅), and total potassium (K) (14.63% in T₁ to 42.64% in T₃) and increase in total nitrogen (N) (55.1% in T₄ to 140.47% in T₁), available phosphorus (P) (4.41% in T₂ to 51.22% in T₅), and pH (2.74% in T₅ to 6.8% T₃). The number of worms during the process has also increased in all treatments and the net weight and growth rate of worms in T₂ and T₅ were higher than other treatments. Therefore, combined Composting-vermicomposting process can be used as an effective method for managing pistachio waste and CD.