Local anaesthetics are commonly used in dental and clinical practices. They are drugs which induce local anaesthesia in patients. These drugs are classified based on two criteria; the duration of action and based on the structure of the local anaesthetics. Based on the duration of action, it can be classified into short, intermediate, and long acting local anaesthetics whereas based on the structure it can be classified into amide ester linked or AA linked local anaesthetic. The classical structure of local anaesthetics includes three parts, the lipophilic part, the hydrophilic part, and the linking part. Furthermore, the mechanism of action of local anaesthetics is mediated through the blocking of nerved conduction via the inhibition of sodium ion channels. They also exert blocking effects on calcium channels and potassium channel. Cocaine is a naturally occurring compound which was used as local anaesthetic before the development of procaine. Procaine is the first synthetic derivative of cocaine which is used as local anaesthetic. Nowadays there are various local anaesthetics used which result from modifications of older local anaesthetics. Local anaesthetics can be used clinical to induce topical anaesthesia, plexus block anaesthesia, IRA, field block anaesthesia, peripheral nerve block anaesthesia, as well as epidural and spinal anaesthesia. The used of AJs together with local anaesthetics have proven to increase the duration of blockade of the local anaesthetics. Currently AJs like epinephrine, alpha-2 receptor agonists, midazolam, dexamethasone, and opioid agonist are used in clinical practice to prolong the duration of blockade of local anaesthetics. The most common adverse effects associated with the use of local anaesthetics include the cardiovascular effects and the central nervous system effects. In addition, there are other side effects like haematological effects, hypersensitivity reactions and teratogenic effects. In this thesis, I will review the use clinical use of local anaesthetics in anaesthesiologic practice, then I will focus on the structural classes of local anaesthetics, recent local anaesthetics used in clinical practice, adjuvants used with local anaesthetics and finally the adverse effects of local anaesthetics used in anaesthesiologic practice.