Due to practical limitations in available 15N rf field strength, imperfections in 15N 180° pulses arising from off-resonance effects can result in significant sensitivity loss, even if the chemical shift offset is relatively small. Indeed, in multi-dimensional NMR experiments optimized for protein backbone amide groups, cross-peaks arising from the Arg guanidino 15Nε (~85 ppm) are highly attenuated by the presence of multiple INEPT transfer steps. To improve the sensitivity for correlations involving Arg Nε–Hε groups, we have incorporated 15N broadband 180° pulses into 3D 15N-separated NOE-HSQC and HNCACB experiments. Two 15N-WURST pulses incorporated at the INEPT transfer steps of the 3D 15N-separated NOE-HSQC pulse sequence resulted in a ~1.5-fold increase in sensitivity for the Arg Nε–Hε signals at 800 MHz. For the 3D HNCACB experiment, five 15N Abramovich-Vega pulses were incorporated for broadband inversion and refocusing, and the sensitivity of Arg1Hε-15Nε-13Cγ/13Cδ correlation peaks was enhanced by a factor of ~1.7 at 500 MHz. These experiments eliminate the necessity for additional experiments to assign Arg 1Hε and 15Nε resonances. In addition, the increased sensitivity afforded for the detection of NOE cross-peaks involving correlations with the 15Nε/1Hε of Arg in 3D 15N-separated NOE experiments should prove to be very useful for structural analysis of interactions involving Arg side-chains.