Background TB-HIV co-infection is the most common problem of African countries, especially, Sub-Saharan countries including Ethiopia. So this study aimed to assess TB-HIV co-infection with its associated factors in patients with Tuberculosis in Northwest Ethiopia. Although the prevalence of TB-HIV was low, the need for strengthening the health extension program especially in urban dwellers also needed to include TB-HIV testing. Objective This study aimed to assess TB-HIV co-infection with its associated factors in patients with Tuberculosis in Northwest Ethiopia. Methodology Institutional based cross-sectional study has been done and a total of 638 subjects participated in the study. The data of the study subjects were collected from the tuberculosis logbook using two trained data collectors who were work in the TB DOTS program and by using a well-prepared checklist and SPSS was used for analyzing data. Results 9.7% (62/638) of TB patients were found to be co-infected with HIV. Among these 32 (11.4%) were females and 30 (8.4%) were males. More infected individuals were found in urban residents 44 (20%) than rural residents and age groups 30–40 years 31 (22.5%) are more infected than the other age group. TBforms, age, and residence were associated with HIV/TB co-infection significantly. Conclusions and Recommendations Although the prevalence of TB-HIV was low, the need for strengthening the health extension program especially in urban dwellers is needed to include TB-HIV testing. Further surveys involving HIV infected TB patients to strengthen and scale-up for TB and HIV is needed.