Purpose – is to analyse the different investment sources for sustainable development of a country and reveal the interaction between investment sources for sustainability and a country's sustainable development.

Research methodology – analysis of scientific sources, collection and systematization of statistical data, a method for sustainable development index calculation, correlation regression analysis.

Findings – each analysed country's progress of sustainable development is expressed as integrated sustainable development index revealed that all analysed countries are gradually increasing their sustainable development results. All three analysed investment sources are strongly affecting countries sustainable development, and stochastic relationship exists between variables.

Research limitations – statistical data with incomplete time series, for which not all the most important sustainable development indicators were selected. The case of three Baltic countries (Lithuania, Latvia, and Estonia) is used for the period 2003–2017. The three main investment sources for sustainable development of a country: assignations of the state budget, EU structural funds, and direct investments, are chosen for the research.

Practical implications – results can be used in calculations for other countries sustainable development and investments interactions. They can be used to evaluate the impact of the different source and contribute to the modelling of their use.

Originality/Value – this article is unique because it reveals the interaction of multiple sustainability sources, in terms of investment sources for sustainability and the results of a country's sustainable development. These sources can be supplemented and adapted to other countries (at least in developed countries EU level).

DOI: https://doi.org/10.3846/cibmee.2019.040