It is a well known theorem that a 3-manifold $M$ with a Heegaard diagram $(V;J_1,\cdots,J_n)$ is a homotopy 3-sphere if and only if there exists an embedding of $V$ in $S^3$ so that $J_1,\cdots,J_n$ bound $n$ pairwise disjoint surfaces $S_1,\cdots,S_n$ in $W=\overline{S^3-V}$. We may assume $S_1,\cdots,S_n$ are incompressible in $W$. But in general, we cannot assume that they are boundary incompressible, since boundary compressions may yield surfaces with more than one boundary component. We describe a version of above theorem in which the involved surfaces are incompressible and boundary incompressible in the corresponding manifold.