Introduction: To improve access to basic health services, Government of India, in 2005, inducted Accredited Social Health Activist (ASHAs) as community health workers. Evaluation of ASHA program in Howrah district of West Bengal indicated low performance of ASHAs in providing maternal care. We conducted an unmatched case-control study to identify factors associated with low performance of ASHA in Howrah district. Methods: We categorized 993 ASHAs as low (cases) and 994 as adequate (controls) performing, based on average incentive received by each ASHA, and randomly selected 261 cases and 261 controls. We interviewed ASHAs to collect information about factors influencing their performance including socioeconomic details, workload, training and support and supervision. We calculated crude and adjusted odds ratios with 95% confidence intervals using simple and multiple logistic regression respectively. Result: Compared to adequate performing ASHAs, low performing ASHAs were more likely to serve larger population than the recommended norm of 1200 [OR: 1.8; 95%CI: 1.2-2.5] or got less supervisory visits by Auxiliary Nurse and Midwife (ANM) in field [OR: 1.75; 95%CI: 1.03-2.98], did not have any stocks of Iron Folate tablets (IFA) [OR: 4.85; 95%CI: 1.37-17.1] and belonged to religious minority [OR: 2; 95%CI: 1.26-3.35]. Conclusion: Low performance of ASHAs was associated with population overburden, not having IFA in stock, less field visit by ANM and religious minority in Howrah district. For improving performance of ASHAs, we recommended recruiting new ASHA, ensuring uninterrupted IFA supply and strengthening supporting supervision. These measures need to focus on ASHAs belonging to Muslim religion. (C) 2017 INDIACLEN. Published by Elsevier, a division of RELX India, Pvt. Ltd. All rights reserved.