Abstract: We present an efficient stratified sampling technique for an ellipse. Our technique provides extensions of previous work for sampling a disk with low distortion; it works for both polar and concentric maps between a square and an ellipse. The mapping preserves adjacency and fractional area, and does not require any numerical computation. As in the previous work, the concentric map demonstrates better performance. Our technique has proven useful in realistic image synthesis using Monte Carlo direct lighting and Monte Carlo path tracing. In conclusion, the proposed technique is stratified, efficient, and feasible for the computer graphics community. Source code is available online.