Value of any firm could be viewed as the sum of the value of its investment projects. Thus, making correct strategic investment decisions is of critical importance to maximizing the value of the firm. In finance literature, decision-making has usually been studied using the scientific rather than the organizational model. In contrast, the current work combines both corporate finance theory and the organizational decision-making theory. Related to that is the choice of methodoloy for empirical research--quite uncommonly, both positivist and interpretive methods are used to study the investment decisionmaking in practice. In addition to a written survey, six in-depth case studies were carried out. Furthermore, as most research on this topic has focused on big companies in Anglo-Saxon countries, studying smaller companies in a smaller country (Estonia) adds some interesting perspectives to the issue. The study could be of interest to all professionals in Corporate Finance and General Management field.