There are genuine fears that bars and restaurants in host cities could run dry, according to Jiji Press.
Concerns were raised at briefings in Sapporo, Hokkaido and Oita which could host the bulk of the expected 400,000 fans to the tournament that runs from September to November.
Running out of beer would mean the loss of "lucrative business opportunities" and could also trigger bad publicity on social media, according to the local report.
Oita Prefecture in south-west Japan – which hosts three pool matches including the All Blacks v Canada and two quarter-finals – has responded, asking brewing companies to improve supplies and bars to extend opening hours to accommodate after-match festivities.
An Oita official told Jiji Press the region's restaurants and wholesalers had admitted the prospect of beer shortages was "a realistic problem".