It has been shown that approximately one in three patients undergoing cataract surgery have >1.0D corneal astigmatism and managing this during surgery is important to achieve good refractive outcomes. One of the widely used ways of reducing preoperative astigmatism during cataract surgery is by using toric intraocular lenses (IOL). It is ideal if this lens has minimal or no postoperative rotation. The aim of this study was to determine the influence of the overall IOL diameter on rotational stability. The IOLs used in this study were ACR6 (12mm) and IDEA 613 XC (13mm) (both CromaPharm GmbH., Austria). Both these IOLs are monofocal, hydrophilic acrylic single-piece with water content of 26%. For the study, all IOLs had markings on them to determine rotational stability postoperatively, but were spherical in design. Sixty eyes of 60 patients were included in the study. Eighteen patients were lost to follow-up at the three month visit. Absolute rotation in the small and large diameter IOL groups was 4.4º (SD: 4.0; range: 0.3-17.8) and 3.0º (SD: 2.4; range: 0.1-7.8) respectively. The differences between the two IOLs were not found to be statistically significant. Thus the authors concluded that the effect of the overall length of an IOL appears to have little impact on early rotation after cataract surgery.