The purpose of this paper is to describe the types of local anesthetics, to show their mutual differences, to expalin the primary mechanism of their action, to emphasize their clinical significance in different types od anesthesia and to describe the role od anesthesiology nurse/technician in the application of local anesthetics with emphasis on complications. For writing this paper, literature in Croatian and English, numerous articles, books, textbooks for secondary medical school, for the study of nursing and medicine, peer-reviewed papers published in medical journals and final and graduate theses were used. Local anesthetics are substances that cause a temporary interruption of the conduction of peripheral nerves by blocking sodium channels, which their primary mechanism of action is actually based on. Namely, it has been noted that the mechanism of action of local anesthetics is largely based on the interaction with sodium (Na+) channels in the nerve membrane. Generally taken, local anesthetics are safe and widely used drugs appliable in a variety of clinical procedures. They are used in different types of anesthesia such as topical, infiltrative, for peripheral nerve blocks and for spinal and epidural anesthesia. They are also used in to treat postoperative pain. They consist of an aromatic group, an amine group and a central chain that determinates the type of bond between these two groups. Depending on the type of bond, local anesthetics are divided into two groups: aminoesters and aminoamides. The pharmacodynamics and pharmacokinetics of local anesthetics differ depending on the type and their characteristics. They need to be well known to understand the mechanism of action of local anesthetics and their application. Certain characteristics of local anesthetics such as liposolubility, binding to plasma proteins, potency, pKa values, their vasomotor activities that affects the rate of onset and duration of action. The onset of action also depends on the type of nerve fiber, the concentration and dose of the drug, the injection site and on the addition of vasoconstrictors and adjuvants. Local anesthetics can cause toxic reactions caused by overdose, multiple injections or accidental intravascular injections. They can also sometimes be the result of allergic hypersensitivity. Adverse reactions to local anesthetics can be local, systemic and allergic reactions. Prevention and treatment of adverse effects are described in detail in this final paper. The anesthesiology nurse/technician as a part of the anesthesiology team participates in all stages of anesthesia and surgery. She/he prepares the patient and the operating room for everything necessary for the application of general or regional anesthesia, prepares medical equipment for surgery, prepares material and monitors the patient during anesthesia and conducts patient care in recovery room after anesthesia. Its role and competencies during all stages of anesthesia and surgery are explained in the paper.