We examined the potential cost of practicing suppression of negative thoughts for subsequent performance in an unrelated task.Cues for previously suppressed and baseline responses in a think/no-think procedure were displayed as irrelevant flankers for neutral words to be judged for emotional valence.These critical flankers were homographs with one negative meaning denoted by their paired responses during learning.Suppression cues as flankers delayed responding to the targets, compared to baseline cues and new negative homographs, but only following directsuppression instructions and not when benign substitutes had been provided to aid suppression.On the final recall test, suppression-induced forgetting (SIF) following direct suppression and the flanker task was positively correlated with the flanker effect.Experiment 2 replicated these findings.Finally, valence ratings of neutral targets were influenced by the valence of the flankers but not by the prior role of the negative flankers.