Recently Y. Baba [Y. Baba, On self-duality of Auslander rings of local serial rings, Comm. Algebra 30 (6) (2002) 2583-2592] proved that certain quasi-Harada rings have a self-duality. In this paper, we also investigate left quasi-Harada rings and obtain several results including an improvement of the result of Y. Baba and applications to self-duality of locally distributive rings. Particularly we shall obtain several results related to Azumaya's conjecture ("every exact artinian ring has a self-duality"). (c) 2006 Elsevier Inc. All rights reserved.