In this article we continue to investigate exotic smooth structures of 4-manifolds studied in [Forum Math. 14 (2002) 915-929]. As a conclusion, we claim that most known simply connected, closed, irreducible, nonspin, smooth 4-manifolds with b(2)(+) odd and large enough admit infinitely many, both symplectic and non-symplectic, exotic smooth structures. (C) 2003 Elsevier B.V. All rights reserved.