Rotating multi-segment slant-hole (RMSSH) SPECT is suitable for detecting small and low-contrast breast lesions since it has much higher detection efficiency compared with parallel-hole SPECT for the same resolution and can image the breast at a closer distance. Our RMSSH SPECT image reconstruction extends a previous rotation-shear transformation based 3D iterative reconstruction method to include non-uniform attenuation compensation. Reconstructed RMSSH SPECT images with attenuation compensation show much improved quantitative accuracy and less image artifacts than without. We conclude that attenuation compensation provides RMSSH SPECT images with improved quality and quantitative accuracy.