Worm infestation is the leading cause of anemia and under nutrition.; children with these infections suffer from developmental disturbances and other serious illness. This study was conducted to assess the knowledge regarding worm infestation among mothers of pre-school children. There is high prevalence of worm infestation in children. So there is an urgent need to educate the mothers regarding worm infestation. The main purpose of the study is to assess the knowledge regarding worm infestation among mothers of preschool children. A quantitative research approach was used to evaluate the knowledge regarding worm infestation among mothers of pre-school children The research design adopted for the present study was simple Descriptive. Samples were mothers of pre-school children in selected areas of Moradabad, sample size was 100 and sampling technique was purposive sampling. The association between demographic variables and knowledge level was determined by chi square test. The result shows that, 48 (48%) mothers of pre-school children had moderately adequate knowledge, 42 (42%) had inadequate knowledge and 10 (10%) had adequate knowledge regarding worm infestation. The maximum mean knowledge score obtained by the subject was 14.50, and the Standard Deviation was 2.5269.The maximum level of knowledge was found moderately adequate. It was found in our study that there was no significant association between knowledge level and demographic variables.