The genus Clerodendrum L.(Family: Lamiaceae) is very widely distributed in tropical and subtropical regions of the world. More than five hundred species of the genus are identified till now, which includes small trees, shrubs and herbs. Ethno-medical importance of various species of Clerodendrum genus has been reported in various indigenous systems of medicines and as folk medicines. The genus is being used as medicines specifically in Indian, Chinese, Thai, Korean, Japanese systems of medicine for the treatment of various lifethreatening diseases such as syphilis, typhoid, cancer, jaundice and hypertension. Few species of the genus like Clerodendrum inerme, C. thomosonae, C. indicum, and C. speciosum are ornamental and being cultivated for aesthetic purposes. The powder/paste form and the various extracts of root, stem and leaves are reported to be used as medicine for the treatment of asthma, pyreticosis, cataract, malaria, and diseases of blood, skin and lung. To prove these ethno-medical claims, some of these species are being extensively studied for their biological activities using various animal models. Along with biological studies, isolation and identification studies of chemical constituents and its correlation with the biological activities of the genus has also been studied. The major chemical components reported from the genus are phenolics, steroids, di-and triterpenes, flavonoids, volatile oils, etc. This review mainly covers the extent of work done on biological activities of various Clerodendrum species such as C. trichotomum, C. bungei, C. chinense, C. colebrookianum, C. inerme, C. phlomidis, C. petasites, C. grayi, C. indicum, C. serratum, C. campbellii, C. calamitosum and C. cyrtophyllum that can be used both in conventional therapy or as replacement therapies for the treatment of various diseases.