DWI is a crucial contrast for prostate cancer, not only for detection but also biopsy guidance and monitoring. Unfortunately, DWI of prostate is plagued by very low SNR, caused by the long TEs needed to encode diffusion with standard imaging gradients. Here we show that by abandoning typical requirements of an imaging gradient, especially nonlinearity, very strong diffusion weighting can be locally achieved using a single standard amplifier, greatly improving DWI image quality. Experiments verify the feasibility of DWI with nonlinear gradients. Though prostate is an ideal first target, this approach could find application in many other organs.