Broccoli contains approximately 2.8 to 3 grams of protein per 100 grams when raw. Different sources report slightly varying amounts, but the typical range is around 2.8 to 3 grams of protein per 100 grams of raw broccoli. For example, the protein content in 100 grams of raw broccoli is about 3 grams according to nutrition data, and one cup (about 90 grams) of raw broccoli provides roughly 2.3 grams of protein.