The study developed an integrated model of the relationship among leader–member exchange (LMX) outcome favorability procedural fairness climate and employee organizational citizenship behavior (OCB). Using three-phrase multilevel data from multiple sources collected from 238 employees working with 42 supervisors at manufacturing firms in China we found that (1) LMX was positively related to outcome favorability and OCB (2) procedural fairness climatemoderated the relationship between outcome favorability and OCB and (3) the indirect effect of LMX on OCB (via outcome favorability) was stronger when procedural fairness climate was high rather than low. The study provides insight on the LMX–OCB relationship and the integration of LMX and fairness research.