Chilli (Capsicum annuum L.) is one of the important vegetable crops in India. Chilli leaf/fruit is affected by many fungal pathogens, but Leaf spot of chilli caused by Alternaria alternata is the most destructive disease leading losses in field as well as market. It adversely affects the fruit quality, quantity and ultimately reduces the market value. An investigation was carried out to test the efficacy of bioagents in vitro by dual culture technique against Alternaria leaf spot of chilli. Four bioagents i.e. Trichoderma viride, T. harzianum, Pseudomonas fluorescens and Bacillus subtilis were evaluated and among them highest per cent growth inhibition (75.67%) was observed in T. harzianum Rifai. NAU followed by T. viride (71.33%), B. subtilis (71.00%) and P. fluorescens (67.33%), respectively. Five phytoextracts were tested at 10% in vitro against the mycelial growth and among them garlic phytoextract was found most effective (75.98%) for inhibiting the pathogen followed by neem (55.26%), tulsi (47.69%), lemon grass (46.71%) and nilgiri leaf extract (44.40%), respectively.