The Japanese mass media has been reporting a rising number of foreign workers in Japan based on data published by the Ministry of Health, Labour and Welfare. The Ministry's data, however, is neither derived from a comprehensive database of foreign workers, nor is it a credible source of information about the foreign workforce. This paper explains how the ministry arrives at its figures, why the reported rapid increase over the past decade is incorrect, and pinpoints flaws in its data collection process. Finally, we suggest a new approach for estimating the total number of foreign workers in Japan at a time when the Japanese government has proposed a significant increase in the number of foreign workers.