Isuzu Motors Ltd. has compiled the following ranking of the world's truck manufacturers, based on the production volumes for the calendar year 2004, using data by manufacturer and by country (with production volumes compared on a single-country basis). The ranking is based on statistics compiled by Isuzu based on data available on the production volumes of medium-duty and larger trucks, or trucks with Gross Vehicle Weights (GVW) of 6.1 tons or higher, from the Automobile Manufacturers' Associations of various countries.

2004 saw a recovery in the global economy, which led to increased production for the Japanese, European, and American manufacturers.
While Isuzu did experience a reactionary fall to the exhaust emission demand in the domestic Japanese market, production increased by 5,678 units (+6.6%) over the previous year thanks to expanded exports to North America and Australia. However, Isuzu's position dropped to third as DaimlerChrysler (Germany) and Freightliner (USA) both experienced significant increases in production. Isuzu Motors maintained its Number One position for the fourth consecutive year in medium-duty truck production, and also retained the top position amongst the Japanese manufacturers overall.