The motor system can employ a number of mechanisms to increase movement accuracy and compensate for perturbing external forces, interaction torques, and neuromuscular noise. Empirical studies have shown that stiffness modulation is one adaptive mechanism used to control arm movements in the presence of destabilizing external force loads (Franklin et al. 2007). Other work has shown that arm muscle activity is increased at movement end for reaching movements to small visual targets (Gribble et al. 2003; Osu et al. 2004; Selen et al. 2006a,b) and that changes in stiffness at movement end are oriented to match changes in visual accuracy requirements such as target shape (Lametti et al., 2007). In this paper, we assess whether limb stiffness is modulated to match spatial accuracy requirements during movement, conveyed using visual stimuli, in the absence of external force loads. Limb stiffness was estimated in the middle of reaching movements to visual targets located at the end of a narrow (8 mm) or wide (8 cm) visual track. We found that when greater movement accuracy was required, we observed modest but reliable increases in limb stiffness in a direction perpendicular to the track. These findings support the notion that the motor system employs stiffness control to augment movement accuracy during movement, and does so in the absence of external unstable force loads, in response to changing accuracy requirements conveyed using visual cues.