By comparing citations and use of articles from international scientific journals, we wanted to explore the relationship between bibliometric and altmetrics indicators. We analyzed data on the articles downloads of the three largest providers of scientific electronic journals in Slovenia: ScienceDirect, SpringerLink and Wiley Online Library. Usage statistics from The Central Technological Library at the University of Ljubljana (CTK) for years 2013, 2015 and 2017 were compared with the journal impact factor SJR from the SCImago database. The purpose of the research was to present the link between the number of article downloads in PDF or HTML form and citation data from the same journals. We have confirmed that the list of scientific journals whose articles have the most downloads is stable over the years. The hypothesis that the changed number of journals of a particular publisher of scientific literature does not affect the number of article downloads, has not been confirmed or refuted. The main of the three research questions was: Do scientific journals with a higher journal impact factor have more article download than journals with a lower journal impact factor? We found out that scientific journals in the first quartile have a greater chance of reaching a larger number of article downloads than journals in the second, third or fourth quartiles. Journals in higher quartiles also have a greater average number of article downloads, although only a few percent of journals from the higher quartile have a larger number of article downloads than journals from the lower quartiles. The hypothesis that journals with a higher journal impact factor have a greater likelihood for a larger number of article downloads than journals with a lower journal impact factor can be confirmed, although exceptions are possible. Thus, altmetric indicators seem to be suitable for complementing bibliometric indicators. Based on these indicators, libraries can provide their users with the highest quality information.