There is growing demand for functional foods and ingredients as a result of their healthpromoting properties. In this work, the potential of common buckwheat flour (Supreme) and bran (Farinetta) in improving upon the phenolic and antioxidant properties of durum spaghetti was investigated. The effects of processing and cooking on these properties were also studied in addition to the cooking quality and carbohydrate digestibility of spaghetti products. The presence of buckwheat significantly (p < 0.05) elevated total phenolic content (TPC), total flavonoids content (TFC), rutin and phenolic acids levels, in flours, uncooked and cooked spaghetti samples. Significant increments were also recorded for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) approaches. Among uncooked spaghetti samples, there were huge increments of between 114 and 522% for TPC, 50 and 242% for TFC, 359 and 1000% for DPPH antioxidant activity, and 101 and 197% for ORAC values of the experimental spaghetti samples over the control. Farinetta contributed more phenolic and antioxidant compounds than Supreme flour. Processing did not cause any significant losses in TPC, but losses ranging from 1.2 to 33.7% in TFC and 42.0 to 55.3% in DPPH antioxidant activity were incurred. Cooking generally resulted in significant losses (p < 0.05) of up to 39% in TPC, 40% in DPPH antioxidant activity, 22% in rutin content, and 55% in TFC among all buckwheat-containing products. Even after these