Essential oils are one of the most important products in the agricultural and food industry, as they are obtained from aromatic plants using various extraction techniques, such as steam distillation or hydrodistillation. However, these methods present challenges, such as low efficiency, limited selectivity, extensive use of solvents and long extraction times. Moreover, the quality of the oils obtained can be affected by hydrolysis or oxidation due to the duration and amount of water used in the process. This review updates the information on Clevenger-type hydrodistillation extraction of four high-value commercial plant species: Matricaria chamomilla, Rosmarinus officinalis, Origanum vulgare, and Eucalyptus spp. The aim is to evaluate the results of original articles, considering the origin and characteristics of the plant material, extraction conditions, yield and metabolites. The searc...