A possible occurrence of a miscibility gap with two critical points (two peaks) is shown using a subregular solution model. As is well known, an ordinary miscibility gap is developed when elements A and B of the A-B system repel each other, i.e, the enthalpy of mixing is positive. A two-peak miscibility gap is formed when the magnitude of this positive enthalpy of mixing is slightly lowered in the intermediate composition range for some reason, such as a magnetic effect or a tendency toward (imperfectly) forming a compound. The two-peak miscibility gap will lead to a new invariant reaction involving only one type of phase (L2 ↔ L1 + L3, etc). It is likely that two-peak miscibility gaps have never been reported because their existence has not been conceived.