Pistachio butter is one of the pasty products made from pistachio kernels. This study investigated color characteristics, peroxide value, fat, protein, and carbohydrate content, and sensory evaluation of pistachio butter enriched with Spirulina algae (0, 5, and 10%) during three months of storage at 20°C. With increasing the percentage of the algae, the sample with 10% of the algae showed the highest protein content (around 25.4%). The highest and lowest fat content was observed in the control and the sample containing 10% algae, respectively. The lowest peroxide value (0.73 meq kg-1) was observed in the sample containing 10% algae compared to others. The level of carbohydrates did not change significantly in all three specimens during storage. Sensory evaluation for taste, sweetness, color, spreadability, mouthfeel, and texture showed that the sample without algae and the specimen containing 5% algae did not differ much. With increasing the algae level to 10%, the sensory evaluation had a significant drop, and in some cases, there was a decrease in the score. The color evaluation of the samples showed that with increasing the algae level, the greenness of the specimen increased, a value decreased, and b value did not show a significant change. Overall, The amount of algae recommended in the pistachio butter formulation is 5%. Manuscript profile