In this paper we address the problem of studying those complex manifolds M equipped with extremal metrics g induced by finite or infinite dimensional complex space forms. We prove that when g is assumed to be radial and the ambient space is finite dimensional then (M, g) is itself a complex space form. We extend this result to the infinite dimensional setting by imposing the strongest assumption that the metric g has constant scalar curvature and is well-behaved (see Definition 1 in the Introduction). Finally, we analyze the radial Kähler-Einstein metrics induced by infinite dimensional elliptic complex space forms and we show that if such a metric is assumed to satisfy a stability condition then it is forced to have constant non-positive holomorphic sectional curvature.