Introduction: Clostridium perfringens is the etiological agent of clostridial myonecrosis and enteritis necroticans. Infections result in exotoxin production, tissue necrosis and unless promptly treated, often result in death. Methods: Tasmannia lanceolata extracts were investigated for C. perfringens growth inhibitory activity by disc diffusion analysis and MIC determination. Toxicity was evaluated by Artemia nauplii bioassay and the most potent extracts were phytochemically evaluated by GC-MS headspace analysis. Results: All T. lanceolata berry and leaf extracts displayed potent C. perfringens growth inhibition. The berry extracts were more potent growth inhibitors than the corresponding leaf extracts, although the leaf extracts were also potent growth inhibitors. The berry aqueous, methanolic and ethyl acetate extracts were particularly potent growth inhibitors, with MIC values of 654, 65 and 329 µg/mL respectively. T. lanceolata leaf also displayed good efficacy, with an MIC of 839, 1255 and 625 µg/mL for the aqueous, methanolic and ethyl acetate extracts respectively. All extracts were nontoxic in the Artemia franciscana bioassay, with LC50 values substantially > 1000 µg/mL. Non-biased GC-MS analysis of the aqueous, methanolic and ethyl acetate berry extracts revealed the presence of high relative levels of a diversity of terpenoids. Conclusions: The lack of toxicity of the T. lanceolata extracts and their potent growth inhibitory bioactivity against C. perfringens indicates their potential as medicinal agents in the treatment and prevention of clostridial myonecrosis and enteritis necroticans. GC-MS metabolomic profiling studies indicate that these extracts contained a diversity of terpenoids, with monoterpenoids being particularly abundant.