The dependence of the defect structure on substrate misorientation is investigated in InGaAs/GaAs(111) multiple quantum well heterostructures. Samples were simultaneously grown by molecular beam epitaxy on GaAs(111)B substrates misoriented 1 degrees off towards [(2) over bar 11] and 2 degrees off towards [2 (1) over bar (1) over bar] under optimized growth conditions for both off-axis substrates, For both substrate misorientations two different dislocation networks are evidenced: first, a triangular 60 degrees misfit dislocation array with [(1) over bar (1) over bar (1) over bar] directions and second, a new dislocation configuration seen for the first time with dislocation lines parallels to [11 (2) over bar] directions. This latter can work as a dislocation multiplication source for In-content above 25% for the structure chosen being more active in 2 degrees off substrates than in 1 degrees off ones. The activation of this new dislocation source may drastically affect the optical properties of the multiple quantum wells.