This text aimed to analyses quantitively how does the Brazilian Supreme Court (STF) applies the solidarity principle (CRFB, 3°, I). Through a jurisprudential research involving decisions from 1988 until 2020, it was reached two conclusions: most decisions use the principle rhetorically; and there is lack of objective theoretical criteria to guide how the principle is applied normatively. To do so, firstly it was established how does occur this application. Secondly, it was fixed the methodology used to gathering data. Through a documental research, it was collected and tabulated the STF judgments. This search was made using keywords "solidarity", "solidarity ADJ principle" and "art. 3°, I, CRFB/88". After reading the brief of all 653 found decisions, it was observed some tendencies on STF posture, what was clearer on 67 judgments classified as most relevant, because on these decisions the solidarity principle was invoked as a ratio decidendi. Finally, this paper interprets the data gathered from the decisions (kind of lawsuit, subject, relevancy) as well the theoretic base of the principle's application, what led to verify that this application is still incipient, despite its crescent tendency on Brazilian legal order, especially on Social Security, where it acts as a hermeneutic guide.