Lantana poisoning has been taking a heavy toll of livestock year after year. All aspects of the problem are reviewed. Lantana poisoning in cattle, sheep, buffalo, and guinea pigs causes obstructive jaundice, photosensitization, and rise in serum glutamic-oxaloacetic transaminase activity. The symptoms could be reproduced in sheep by administration of purified Lantadene A. Liver and kidneys are the most affected organs during lantana poisoning. Intoxication of guinea pigs with Lantana camara leads to marked alterations in major tissue constituents in liver and kidneys. Hepatic and renal xanthine oxidase activity is also elevated during lantana poisoning. No antidote is available against the toxic section of Lantana camara. Symptomatic treatments have been proposed with limited success. Knowledge of the biochemical mechanism of lantana intoxication at the cellular, subcellular, and molecular levels is essential in order to evolve a successful antidote and more rational therapy during lantana intoxication.