The mean global lifetime risk of neurological disorders such as stroke, Alzheimer's disease (AD), and Parkinson's disease (PD) has shown a large effect on economy and society. Researchers are still struggling to find effective drugs to treat neurological disorders and drug delivery through the blood-brain barrier (BBB) is a major challenge to be overcome. The BBB is a specialized multicellular barrier between peripheral blood circulation and neural tissue. Unique and selective features of the BBB allow it to tightly control brain homeostasis as well as the movement of ions and molecules. Failure in maintaining any of these substances causes BBB breakdown and subsequently enhances neuroinflammation and neurodegeneration. BBB disruption is evident in many neurological conditions. Nevertheless, the majority of currently available therapies have tremendous problems with drug delivery into the impaired brain. Nanoparticle (NP)-mediated drug delivery has been considered a profound substitute to solve this problem. NPs are colloidal systems with a size range of 1-1000 nm which can encapsulate therapeutic payloads, improve drug passage across the BBB, and target specific brain areas in neurodegenerative/ischemic diseases. A wide variety of NPs has been displayed for the efficient brain delivery of therapeutics via intravenous administration, especially when their surfaces are coated with targeting moieties. Here, we discuss recent advances in the development of NP-based therapeutics for the treatment of stroke, PD, and AD, as well as the factors affecting their efficacy after systemic administration.