Let K be the familiar class of normalized convex functions in the unit disk. Keogh and Merkes proved the well-known result that max f ∈K |a 3 − λa 2 2 | max{1/3, |λ − 1|}, λ ∈ C, and the estimate is sharp for each λ. We investigate the corresponding problem for a subclass of quasi-convex mappings of type B defined on the unit ball in a complex Banach space or on the unit polydisk in C n . The proofs of these results use some restrictive assumptions, which in the case of one complex variable are automatically satisfied.Keywords Fekete-Szegö problem, quasi-convex mappings of type A, quasiconvex mappings of type B, quasi-convex mappings of type C MSC 32A30, 32H02, 30C45