Background/aim: Almond hull is produced in high amounts and mostly used as livestock feed. This study was designed to examine the impact of almond hull powder (AHP) administration on lipid profile and antioxidant activities in plasma and liver in hyperlipidemic rats. Materials and methods: As the first step, the antioxidant capacity and radical scavenging activity of AHP were determined using calorimetric methods. Then 36 adult male Wistar rats were randomly divided into 6 groups: group 1 with oral administration of 10% AHP, group 2 with oral administration of 20% AHP, group 3 with oral administration of 30% AHP, group 4 as a positive control with a high cholesterol diet, group 5 as a negative control with a normal diet, and group 6 as a sham group with a normal diet and 20% AHP. The rats were fed a hypercholesterolemic diet to create a hyperlipidemia rat model and then they received AHP for 30 days. Results: Antioxidant and radical scavenging activity of the AHP extract showed a high content of antioxidants that exert potent radical scavenging activity. According to the results obtained, upon the administration of AHP the levels of cholesterol and triglycerides significantly decreased, while the antioxidant capacity of plasma increased. Conclusion: AHP with bioactive compounds and fiber can reduce total cholesterol and triglycerides and improve serum antioxidant capacity.