Delayed maturity in soybean, Glycine max (L.) Merr., occurred in response to infestation by southern green stink bug, Nezara viridula (L.), in 4 yr of field studies. Maturity delays followed stink bug infestation that occurred only during the pod set and filling stages (R3–R5.5), and infestations at R3–4 and R5 resulted in delayed maturity more consistently than did infestation at R5.5. Infestation levels of six stink bugs per 0.3 m of row for 7–14 d generally were required to delay soybean maturity. The greatest impact on seed yield and quality parameters followed stink bug infestations that occurred during R3–R5.5, which corresponded closely with the periods of infestation that resulted in delayed maturity. If both delayed maturity and yield reduction are considered, the pod elongation through late pod filling stages were most critical for protecting soybeans from southern green stink bugs.