In recent years, the spread of generic drugs (GE) has attracted attention in order to reduce medical costs stemming from their use. Though GE are guaranteed to be bioequivalent to their brand name counterparts, only a few medical institutions have fully adopted them.To evaluate measures taken by companies against problems preventing the spread of GE, we performed a questionnaire survey in 33 companies selling a GE of omeprazole, pravastatin sodium or dextromethorphan hydrobromide. It revealed that most of the companies could provide the information needed by medical institutions when adopting GE, such as results of stress testing and records of supply to other medical institutions. It also showed that the problems associated with GE, such as measures for ensuring supplies in an emergency and insufficient information in package inserts, had already been solved, or were in the process of being solved, though there was a difference in the extent to which this had been done. To ensure the greater spread of GE in the future, it may be necessary for manufacturers to be more active in providing information and for medical institutions to collect information on them as well.