In this paper, we study the asymptotic behavior of the Pseudo‐Jacobi polynomials Pnfalse(z;a,bfalse) as n→∞ for z in the whole complex plane. These polynomials are also known as the Romanovski–Routh polynomials. They occur in quantum mechanics, quark physics, and random matrix theory. When the parameter a is fixed or a>−n, there is no real‐line orthogonality. Here, we consider the case when the parameters a and b depend on n; more precisely, we assume a=−(An+A0),A>1 and b=Bn+B0, where A,B,A0,B0 are real constants. Our main tool is the asymptotic method developed for differential equations with a large parameter.