The purpose of the study is to analyze employee volunteerism. This issue had not been studied on a broader international level earlier. This research firstly discovers altruism and volunteerism values in the economy. Then, based on the third-party model, observes each part, where participants are the (1) volunteer (employee) (2) company (and its CSR activity) and (3) an external organization, which manages this type of formal volunteerism. Each participant was analyzed through comprehensive analysis using descriptive and inference statistics and classification methods on complex, extensive secondary databases. Altogether, more than 10,000 respondents’ answers are examined from two worldwide surveys, and further ten international statistical indicators and indices are explored. These methods result in volunteer characteristics on a personal level, afterwards in country classification, which provides a cultural comparison of the employee volunteerism. Our findings prove that demographical differences do not, but company-level actions influence the intensity of formal volunteerism. Moreover, three main clusters (formed from 43 countries) show different values. This diversity might partly be caused by measurement fragmentations and lack of internationally accepted definitions and theories. This paper aims to provide a broader overview of the topic, which might be a useful starting point for the forthcoming aggregated conceptualization. Employee volunteers’ behavior arises from the personal value of volunteerism. However, the attendance and intensity of voluntary activity are primarily influenced by the environment (e.g., life period, living and working situation). Employee volunteerism programs are an important and essential part of CSR at the company level, and strongly frames this activity, where employee volunteerism could associate each participant’s interests and improve their values. However, the practices may differ in each country and in each sector. The current pandemic rewrote the traditional volunteerism model and our projection. The last chapter provides a preliminary study about how employee volunteerism could work in this extraordinary, COVID-19 situation.