ABSTRACT: Charge symmetry breaking (CSB) in the nucleon-nucleon system offers one of the most stringent tests of our understanding of physics, be it at the level of meson exchange or the underlying quark degrees of freedom. Indeed, charge symmetry is conserved if one ignores electromagnetic corrections and the mass difference between the up and down quarks; that mass difference is not determined by chiral symmetry and experimental data from pion-nucleon scattering do not constrain it. A precision measurement of CSB, which was carried out at TRIUMF and complements elastic neutron-proton scattering experiments at both IUCF and TRIUMF, may help constrain the up and down quark mass difference and lead to a richer understanding of the quark effects in the NN system. The observable of interest is the forward-backward asymmetry (A_fb) in np -> d(pi)^0, which must be zero in the center-of-mass system if charge symmetry is conserved. Afb has a predicted value that ranges between (-35 ->+70) ´ 10-4 with the dominant contributions being an order of magnitude larger than those of the elastic scattering CSB measurements. Like other measurements of "fundamental symmetries" this is a highly intriguing experiment in that the physics being investigated is of high interest and the experiment itself is challenging. The experimental challenges and results will be discussed.