The production of rabies virus from baby hamster kidney-Ankara 66 (BHK-An(66), HUKUK 99050302) monolayer cells was examined in a packed-bed reactor containing non-woven polyester fabric (NWPF) discs. At first, growth characteristics of the cells were determined in static culture. The suspension culture studies were realized in a I litre spinner basket with NWPF support. BHK-An,, cells (inoculation density, 5 x 10(4) cells ml(-1)) were maintained in the reactor loaded with 5 g(.)l(-1) carrier. The culture medium was Eagle's minimal essential medium supplemented with 10% (v/v) fetal bovine serum at 37 degreesC. During the culture, the medium was sampled daily to assess glucose and lactate concentrations. At the end of the 7 day culture period the cell density was found to be 2.2 x 10(7) cells ml(-1), and the reactor was inoculated with 5 mi [1.7 x 10(6) focus-forming units (ffu) ml(-1)of the CVS I I (Challenge Virus Standard) strain of rabies virus. After a 72 h incubation period, the cultures were stained with fluorescein-conjugated anti-rabies globulin and were observed using a fluorescence microscope. Virus titres determined by the Spearman-Karber method were 2.2 x 10(5) ffu ml(-1). In conclusion, NWPF packed reactors can be considered as a suitable system for the large-scale production of rabies virus.