Some recent developments in the theory of multicritical points are reviewed with emphasis on the spin‐flop bicritical point (T b ,H b ) in anisotropic antiferromagnets, such as MnF2. An extended scaling theory is stress on the existence of optimal scaling axes. Renormalization group calculations for competing (perpendicular and parallel) order parameters justify the bicritical scaling theory and yield values for the corresponding exponents. Specific predictions follow for the vanishing of the magnetization discontinuity across the spin‐flop line as T→T b ‐, for the (M∥, H∥) bicritical isotherm, for the asymptotic variation of the susceptibility, specific heat, and scattering intensity, and for the shape of the paramagnetic phase boundaries near the bicritical point. The spin‐flop phase diagram−in (T, H∥, H⊥) space is analyzed, and the universality of magnetic tricritical points is discussed briefly.