Recent developments are reviewed in the area of leaky-wave analysis of two-dimensional (2-D) leaky-wave antennas. Recent results are reviewed in three areas: (1) new beamwidth formulas for 2-D leaky-wave antennas, (2) leakywave analysis of wideband Fabry-Pérot cavity antennas, and (3) leaky-wave analysis of 2-D periodic leaky-wave antennas (those that radiate from higher-order space harmonics).