The aim and research problem of this thesis was to explore the safety deficiencies observed in construction projects on the basis of the written entries made in the safety monitoring form and their content. A parallel research problem was to use a questionnaire survey to explore the attitudes and opinions of employees at the construction company Asko Kokkonen Oy towards the implementation of safety in construction site conditions.

The theoretical part of the thesis deals with the history of occupational safety and current practices. Documents that promote and guide safety include occupational safety legislation and regulations, the act on safety and health supervision and occupational safety and health cooperation.

The material examined in the thesis focuses on the entries in the safety monitoring forms of line renovation projects implemented during 2014–2019, in which the company has acted as the main contractor. The second research material was a survey for the company's personnel. The research methods were quantitative.

The research results provided information describing the recording activity of the occupational safety inspection forms of the company, observations on the most common topics of safety deficiencies in line renovation projects, and the opinions of the company's personnel on safety and occupational safety training needs.

The most significant conclusion drawn was the variable recording activity of inspection reports. The most common points to be improved in the weekly safety monitoring were the use of personal protective equipment, the general order of the construction site, the protection of openings during working hours and dust control. Respondents were of the opinion that the construction site where they work is safe. Similarly, personal protective equipment is mainly used on site and also by the respondents themselves. The research results on the use of personal protective equipment on the construction site were different when compared to surveys and inspection reports. Extending the survey to partners would be relevant as a topic for further research.