Clostridium difficile is a major nosocomial pathogen that has become a health concern worldwide. Due to its strict anaerobic growth requirements, dormant endospores are its main infectious and transmissible morphotype. C. difficile infection is initiated by germination of endospores to vegetative cells within the intestine, followed by the production of toxins that cause epithelial damage. During infection, C. difficile starts a sporulation pathway that produces more spores that both persist in the patient and are shed into the environment, thus increasing the chance of disease transmission and recurrence. In this study, the effects of 20 natural products on four stages of the endospore life cycle of C. difficile was investigated against three reference strains and one clinical isolate including both toxigenic and non-toxigenic strains. The effect of products on sporulation of C. difficile spores was determined using microscopy and conventional spore recovery assay and their impact on spore germination and outgrowth was investigated using a standard germination and outgrowth assay. Moreover, the sporicidal activity of five products shown previously to have bactericidal activity against vegetative cells was assessed using a plate recovery assay. Of the 20 products, only onion juice and coconut oil inhibited spore formation in all 4 isolates by 50 to 90% compared to the control. Inhibition was observed also, although to a lesser extent, by ginger juice. No effect was detected on the germination stage, but the later stage of outgrowth was inhibited by several products, with artichoke extract having the greatest effect at a concentration of 75 mg ml-1. In addition, peppermint oil and trans-cinnamaldehyde showed sporicidal activity with log10 reductions in C. difficile spores ranging from 0.54 to 2.19. No single product inhibited all four stages and was also sporicidal. Further studies are required to determine the mechanism of action of natural products against C. difficile spores and their efficacy in vivo.