A mixer for mixing immiscible fluids includes a mixer housing defining a flow passage therethrough from a first fluid inlet to an outlet thereof. An upstream portion of the flow passage defines a main longitudinal axis. A second fluid inlet is provided downstream of the first fluid inlet in fluid communication with the upstream portion of the flow passage. The second fluid inlet is offset with respect to the main longitudinal axis of the flow passage to introduce fluid along a path that is offset with respect to the main longitudinal axis for inducing swirl on fluids introduced at the first and second fluid inlets. In certain embodiments, a mixer section is included having a flow constriction defined in a downstream portion of the flow passage with a flow area smaller than that of the upstream portion of the flow passage for enhancing turbulent mixing of fluids therein.