Pickling of piquin pepper was performed assisted by an initial vacuum pulse. This study was aimed at evaluating the effect of acetic acid and sodium chloride concentrations in pickling solutions, and processing time on stability, quality, and mass transfer parameters of piquin pepper. Model equations were developed for solute gain (SG), WL/SG ratio, water activity (a_w), pH, firmness and color index (CI) of piquin pepper. Pickled piquin pepper gained pickling solutes (up to 7.9%) and water (-WL), producing WL/SG values up to -15. In comparison with fresh pepper, pickled pepper firmness decreased between 2 and 59%. Color changed from bright green to different tones of olive green (CI from -0.8 to -1.8). Pickling of piquin pepper during 15 days in 2.8% acetic acid and 13% sodium chloride gave the best stability parameters (a_w=0.933 and pH=3.0).