Synchronized Q-switching between quasi-three-level and four-level lasers is interesting for sum-frequency generation into the blue and ultraviolet. We report, for the first time, stable synchronized Q-switching between a quasi-three-level laser at 946 nm and a four-level laser at 1064 nm in an all passive approach. While timing jitter of the individual free-running lasers were on the order of 10 μs, the relative timing jitter, defined as one standard-deviation of the experimental data, was only 9 ns between the two synchronized pulses. The minimum delay between the two pulses was 64 ns during stable operation, which gave a 79% temporal overlap when normalized against the zero-delay scenario. Preliminary results show promise for non-linear frequency conversion, which could lead to high power pulsed blue and ultraviolet lasers.