In order to characterize and study the bioactivities of individual plant species and to determine how these characteristics are modified when preparing blends, five different plant species were selected: Erica australis L., Genista tridentata L., Melissa officinalis L., Mentha spicata L., and Prunella vulgaris L. Infusions prepared from each plant species and from three selected mixtures were analyzed in terms of nutritional values, phenolic compositions, and bioactive properties (antioxidant, antimicrobial, cytotoxic, and anti-inflammatory activities). The major compound detected in M. officinalis, M. spicata, and P. vulgaris infusions was rosmarinic acid, whilst in E. australis and G. tridentata flavonoid derivatives such as quercetin and genistein were identified. P. vulgaris and M. officinalis presented the best results in TBARS and OxHLIA assays, respectively. M. spicata and all mixtures presented anti-inflammatory activity. M. spicata showed the best cytotoxic properties and antimicrobial activity, and none of the infusions showed hepatotoxicity for non-tumour cells.