The very nature of scientific activity and information, which are meant to be shared, is the starting point in defining a scientific journal, and the criteria according to which its value and role are determined. The authors aim at analysing some criteria that define the quality of scientific journals considering their visibility and impact. The concept of open access for journals is analysed in point of its advantages and disadvantages, since it differs greatly from the subscription-based access, whether we talk about institutional or individual subscriptions. The authors are in favour of the concept of public access, considering that it gives a journal more visibility, on the condition that article processing charges are reduced. The essential condition for a journal to become renowned is to be as visible as possible. The concept of open access is beneficial, supports instruction through and for scientific research, regardless of educational level. The aim of this paper is to emphasise the modalities, specificities and bibliometric performances (percent of citable documents, impact factor and immediacy index) of open access versus subscription-based access, as well as to investigate whether the use of open access concept determines an increase of the journals' quality, study applied to the analysis of Hindawi Publishing Company journals and Multidisciplinary Digital Publishing Institute (MDPI) journals.