The blood–brain barrier (BBB) poses significant challenges for drug delivery to the brain, particularly for neurological diseases. Nanoparticles (NPs) have emerged as versatile and promising tools to enhance BBB penetration and drug delivery. This review discusses the characteristics of NPs that facilitate BBB penetration, including their size, shape, chemical composition, surface charge, and conjugation with various biological or synthetic molecules. The article also covers the coating of NPs with surfactants and provides an overview of in vitro and in vivo models used to study NP penetration through the BBB. Additionally, it explores the impact of BBB impairment under pathological conditions and how this can be leveraged to enhance drug delivery. The review emphasizes the need for future studies to uncover the therapeutic properties of NPs and their potential as therapeutics beyond delivery systems. Overall, NPs are highlighted as a highly promising strategy for precise BBB targeting and drug delivery in neurological disorders.The blood–brain barrier (BBB) poses significant challenges for drug delivery to the brain, particularly for neurological diseases. Nanoparticles (NPs) have emerged as versatile and promising tools to enhance BBB penetration and drug delivery. This review discusses the characteristics of NPs that facilitate BBB penetration, including their size, shape, chemical composition, surface charge, and conjugation with various biological or synthetic molecules. The article also covers the coating of NPs with surfactants and provides an overview of in vitro and in vivo models used to study NP penetration through the BBB. Additionally, it explores the impact of BBB impairment under pathological conditions and how this can be leveraged to enhance drug delivery. The review emphasizes the need for future studies to uncover the therapeutic properties of NPs and their potential as therapeutics beyond delivery systems. Overall, NPs are highlighted as a highly promising strategy for precise BBB targeting and drug delivery in neurological disorders.