Crack growth characteristics of fluoroelastomer vulcanizates filled with carbon black (size : 30 nm) and short Kevlar fibre (6 mm length) under static and dynamic conditions have been evaluated. The fibre reinforced vulcanizate shows higher J(c) values (80 kJ m(-2)) than both the carbon black filled sample (44 kJ m(-2)) and the control (15 kJ m(-2)). However, under dynamic fatigue conditions, the black filled sample is stronger.