ISM (International Safety Management) Code is a rule that regulates safety on board ships. The ISM Code is useful for improving safety on board ships, especially for passenger ships which have the main priority of maintaining the safety of the lives of passengers in particular and the ship's crew in general. But in its application, there are several factors that hinder the implementation of the ISM Code. This study aims to determine how the implementation, inhibiting factors and steps that can be taken to improve the implementation of the ISM Code on KM Sinabung.  The research method used in this research is descriptive qualitative method. Data sources were taken from primary and secondary data. Data collection techniques through observation, interviews and documentation studies during researchers carrying out sea practice at KM. Sinabung. Data analysis techniques used are data collection, data reduction, data presentation and conclusion drawing. Testing the validity of data using the source triangulation method. The results showed that the implementation of the ISM Code on board KM. Sinabung has been implemented but not yet optimal. Lack of knowledge, awareness and supervision of the crew related to safety is a factor inhibiting implementation on board KM. Sinabung is not optimal. So that efforts that can be made to improve the implementation of the ISM Code are to carry out safety induction, maximize training and competence, install safety posters to provide strict sanctions against violators so that the implementation of the ISM Code can be carried out optimally.