Conventional medical education does not provide adequate training to undergraduates to resolve healthcare-related ethical dilemmas. This quasi-experimental study using a pre-post design was conducted to assess knowledge, attitudes and practices in healthcare ethics (HCE) and evaluate the effectiveness of the introduction of HCE in ethical behaviour among medical undergraduates at the Mahatma Gandhi Institute of Medical Sciences in Sevagram, India. All the participants thought that knowledge of HCE is important. There was an improvement in the knowledge of HCE after the intervention, as both weighted mean and percentage consensus improved. In Phase I, absolute learning gain, relative learning gain, and normalised gain “g” were significantly higher after the intervention. In Phase II, the intervention showed low and moderate effectiveness in improvements in the affective and psychomotor domain, and in the ability to handle ethical issues, respectively; but no significant improvement in communication skills. During the feedback session, it was seen that a majority of the participants thought that it is the need of the hour to introduce skill-based HCE into their curriculum from the first year. It can be concluded that it is possible to improve knowledge, and affective, psychomotor ability to handle ethical issues among undergraduate medical students with formal training.