If you pursue a course at a degree level or above you may be permitted to work while on an international student visa in most of the countries. But before undertaking any paid work, make sure that your visa allows the same. The opportunity for students to work during their studies period varies from country to country. For example, the US only allows graduate school students to work for 20 hours a week within the university premises. The rules are a little different in the UK but carry similar time limitations. However, summer and winter breaks offer options for various internships and more work hours but international students have to check with job and placement centers in their universities. The university careers service is also a useful source of information.