The morphologies of A(m1)B(2n)A(m2) and A(m)B(n)C(p) triblock copolymer melt films confined between two hard walls are investigated via Monte Carlo simulations on simple cubic lattices. Depending upon the thickness of the film, parallel, perforated, mesh-like and normal lamellae can occur in A(5)B(10)A(5) melts. Consequently, no sudden transition occurs between the parallel and normal lamellae. The ratio m1/m2 also affects the morphology of the A(m1)B(2n)A(m2) melts. As the ratio is decreased, the microdomains become softer and the boundaries between different phases less sharp. In the A(m)B(n)C(m) systems, lamellar morphologies are present in a wide composition range, when the interaction energies between them and between each of them and vacancies (V) is an element of(AB) is an element of(AC) is an element of(BC) = 0.3, is an element of(AV) is an element of(BV) is an element of(CV) = 0, is an element of(AA) is an element of(BB) is an element of(CC) is an element of(VV) = 0 and the walls are neutral. By increasing the interactions between different kinds of segments from 0.3 to 1, major changes in morphology take place. The preference of the walls for various blocks greatly affects the morphologies and orientations of the microdomains.