PurposeThe financial policies of the modern world corporations and their investment decisions are generally considered as interrelated because the agency problems, associated with the debt level and its maturity structure, give rise to incentives for overinvestment or underinvestment. The present study empirically investigates the linkage between debt maturity structure and firm investment in a financially constrained environment, using Pakistan as a case study, to determine how the institutional environment in which firms operate affect these decisions and their linkage.Design/methodology/approachThe empirical analysis is carried in a panel data setting using panel regression models as the baseline methods. Moreover, generalized methods of moments (GMM) estimators are used, coupled with the instrumental variables approach, for robustness and improving the efficiency and consistency of estimates.FindingsResults suggest that firms rely more on short financing in Pakistan. Thus, given the capital structure which is characterized by higher proportion of short-term financing, the higher level of leverage is less likely to cause underinvestment problem. However, the underinvestment problem do persists in the firms that have higher portion of long-term debt. These findings imply that the debt-overhang problem may persist even in the financially constrained environments where attractive investment opportunities are limited, and long-term financing is difficult to acquire.Originality/valueThis study contributes to the literature by revealing how corporate investment and financing decisions and their linkage is influenced by the institutional environment of the less developed countries which is characterized by underdeveloped financial markets, inefficient legal system and weak investor protection system.