Acetylcholine is a neurotransmitter that plays a significant role in a variety of physiological functions. Cholinergic neurons synthesize, store, and release acetylcholine and are also responsible for sympathetic and parasympathetic responses of the autonomous nervous system. The wide range of functions that the cholinergic system plays explains the diverse range of therapeutic potential that targets this system. Over the decades, cholinergic and anticholinergic drugs are utilized as treatment options for various conditions including ophthalmology, neurogenic bladder, myasthenia gravis, dementia, postoperative urinary retention, xerostomia, anticholinergic overdose, snakebites, Parkinson’s disease, and Alzheimer’s disease. Alongside, they are also investigated for various promising therapeutics. This chapter provides an overview of the cholinergic system pharmacology, functions in the body, cholinergic and anticholinergic compounds, and their potential role in the medical field. Further, the chapter highlights the updates on the cholinergic compounds currently used to treat various conditions as well as compounds under investigation.