To understand whether the intrinsic capacity of the fetal brain in vitro self-organizes into organoids (FeBOs) to secrete a tissue-like “matrisome” is linked to the maintenance of cell-to-cell organization and integrity, we compared the secretome of intact FeBOs and FeBO-derived neurospheres. We also performed side-by-side comparative proteomic analysis of FeBOs and human fetal brain tissue to investigate if the extracellular matrix (ECM) production in the FeBOs resembled a proper tissue-like ECM niche. Moreover, we also included proteomic analysis of unguided pluripotent stem cell (PSC)-cerebral organoids and PSC-cortical spheroids to understand how the human brain tissue ECM-niche compared not only to the FeBOs but also to PSC-derived 3D brain models.