In this book, we introduce the notions of implicative ideal with respect to an element of a BH-algebra in ordinary and fuzzy senses. We state and prove some theorems which determine the relationships among these notions and other ideals of a BH-algebra in ordinary and fuzzy senses and by some examples. We show that these notions are different. Also, we consider some properties of implicative ideal of a BH-algebra in ordinary and fuzzy senses and link them with these new notions.