Thiourea and guanidine substructural units are of significant importance as the compounds containing these core units either in the open or the cyclic form are known to display an array of pharmacological properties. This brief review assimilates the literature on the medicinal significance of thiourea and guanidine derivatives with respect to antimalarial and antimicrobial activities. Keywords: Thiourea, Guanidine, antimalarial, antimicrobial, antifungal.