Pregnancy is a vital event in a woman's life. Many primigravida mothers do not have adequate knowledge regarding birth preparedness. Video-assisted teaching on birth preparedness helps improve the level of knowledge. The aim of the study was to evaluate the effectiveness of video-assisted teaching on knowledge regarding childbirth preparedness among primigravida mothers. A pre-experimental, one-group pre-test, post-test design without a control group was adopted for the study. Fifty primigravida mothers were selected using the non-probability purposive sampling technique. A self-structured knowledge questionnaire was used to collect the required data. The pre-test was conducted after 37 weeks of gestation. The video was played for 20 minutes to make the subjects aware of childbirth preparedness. The posttest was conducted on the day of labor using the same self-structured questionnaire. At the time of labor, maternal pain perception was assessed using the Wong-Baker pain coping scale. The collected data were tabulated and scrutinized using descriptive and inferential statistics. The results show that the majority of the sample had a moderate level of knowledge, while no one had adequate or inadequate knowledge in the pretest. In the post-test, the majority of the samples (30%) had an adequate level of knowledge, 13% had a moderate level, and 7% had an inadequate level of knowledge in childbirth preparedness among primigravida mothers. The pre-test mean knowledge score was 14.82 with a standard deviation of 1.98, and in the post-test, the score was 26.28 with a standard deviation of 1.38. The mean difference was high and statistically significant. The study concludes that video-assisted teaching was effective in improving the level of knowledge of primigravida mothers regarding childbirth preparedness.