Universal Journal of Accounting and Finance 9(3): 285-294, 2021 http://www.hrpub.org DOI: 10.13189/ujaf.2021.090302 Internal Control System Quality and Decision-Making Success: The Role of the Financial Information Quality Albertina Paula Moreira Monteiro 1,* , Joana Andreia Machado Vale 2 , Catarina Libório Morais Cepêda 2 , Eduardo Manuel de Almeida Leite 3 1 Porto Accounting and Business School, Polytechnic of Porto, CEOS.PP, Porto, Portugal 2 Porto Accounting and Business School, Polytechnic of Porto, Porto, Portugal 3 Higher School Technology and Management, University of Madeira, CiTUR, Portugal Received February 24, 2021; Revised April 22, 2021; Accepted May 16, 2021 Cite This Paper in the following Citation Styles (a): [1] Albertina Paula Moreira Monteiro, Joana Andreia Machado Vale, Catarina Libório Morais Cepêda, Eduardo Manuel de Almeida Leite , "Internal Control System Quality and Decision-Making Success: The Role of the Financial Information Quality," Universal Journal of Accounting and Finance, Vol. 9, No. 3, pp. 285 - 294, 2021. DOI: 10.13189/ujaf.2021.090302. (b): Albertina Paula Moreira Monteiro, Joana Andreia Machado Vale, Catarina Libório Morais Cepêda, Eduardo Manuel de Almeida Leite (2021). Internal Control System Quality and Decision-Making Success: The Role of the Financial Information Quality. Universal Journal of Accounting and Finance, 9(3), 285 - 294. DOI: 10.13189/ujaf.2021.090302. Copyright©2021 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract This study aims to develop and evaluate a Decision-Making Success contingency model to assess its dependency on Internal Control System Quality and Financial Information Quality. The authors developed a study based on a sample of 381 Portuguese managers. The structural equations model was used in the analysis of causal relationships between different constructs. Results show that Internal Control System Quality contributes directly to Decision-Making Success. Moreover, Internal Control System Quality and Financial Information Quality are determining factors for Decision-Making Success since Internal Control System Quality has a significant direct impact on Financial Information Quality (with a 64% coefficient of determination) and indirect on Decision- Making Success. The model justifies 67% of the variance of the dependent variable. This research covers a literature gap, since it identifies innovatively, two independent variables that are determinant for Decision-Making Success from the Portuguese companies’ manager perspective. This study is relevant to literature development, as it develops and evaluates an original model, and to managers, in the sense that it identifies factors that contribute to Portuguese companies’ success. Keywords Contingency Theory, Decision-Making Success, Financial Information Quality, Internal Control System Quality 1. Introduction With the progress of economic activity, accounting has been an essential tool to support management in decision- making [1]. Therefore, accounting information is an important resource in the decision-making process. Akhtar and Liu [2] (p. 390) indicate that the accounting information “should be used by the external and internal evaluators of the company, to guide better decisions”. Thus, the literature suggests that accounting is a vital tool in the management of an entity and decisive for decision-making [3]. However, decision-makers need useful and quality accounting information to support their decisions [4, 5]. Hence, a high- quality decision needs high-quality information [6]. According to Fitriati and Susanto [4], the accounting information system quality and the quality of financial reports influence the Decision-Making Success. Thus, accounting information system allows the obtaining, registering, saving, and processing of data to provide useful financial information to decision-makers [7]. However, the