Background: - Human hookworm is a soil-transmitted helminth infection caused by either Necator americanus or Anclystoma duodenale.Globally it is a major cause of morbidity and predominantly affects the poorest population. Transmitted primarily by larval invasion of exposed skin, the adults inhabit the host small intestine, where they consume host blood. The resultant chronic iron deficiency anemia can lead to stunted growth and cognitive deficits in children, reduced work capacity in adults, and a variety of pregnancy complications. Objective:-To assess prevalence of hook worm infection &its associated factors among adult outpatient attendants in health facilities of North Mecha District, North West Ethiopia 2020/2021. Method: - Afacility based cross-sectional study was conducted from December 10/2020 to January 8/2021. Six out of 11 Health facilities were selected by Lottery method& study participants were selected by systematic random sampling technique. Data collectors and supervisors were trained. Pre tested Amharic version questionnaire was used to collect data using face to face interview technique and stool sample was examined in the Laboratory. Data was coded and entered into SPSS version 23 software. A total of 539 samples were included in Analysis.Bivariable logistic regression analysis was used to identify factors associated with prevalence of hook worm infection.Those variables <0.2 p-value were entered into multivariable logistic regression analysis to identify statistically significant independent factors when the effect of other variables were adjusted. Adjusted odd ratio at 95% CIand p-value< 0.05 was presented. Result: - The prevalence of hookworm infection was 20%. Habit of walking in barefoot in outdoor (AOR=6.49, 95% CI ;( 2.753-15.302)), fingernails hygienic status (AOR=2.534, 95% CI (1.354-4.74)) and information about hookworm infection (AOR=6.013, 95%CI (2.625-13.776)) were significantly associated with hookworm infection. Conclusion: - The prevalence of hookworm infection is high. Had habit of walking in barefoot ,had dirty fingernails and had no information about hookworm infection were positively associated with hookworm infection.Giving targeted health education, regular shoe wearing and behavioral change communication to reduce habit of walking in barefoot are essential to reduce prevalence of hookworm infection among adults. Keywords: - Hook worm infection, Associated factors, Adult Outpatient attendant and North Mecha district.