This paper investigates the effect of small tabs placed at the exit plane of an axisymmetric smooth contraction on passive scalar mixing in a slightly heated turbulent jet. It is shown that the presence of tabs profoundly distorts the jet flow field and consequently modifies the scalar mixing characteristics significantly. Tabs cause the mean temperature to decrease more rapidly with downstream distance, implying an increased mixing rate. Furthermore, it is found that two tabs distort the jet from the axisymmetric state more dramatically than four tabs.