Negative sentences are hard to process when they are presented out of context. When embedded in a context of plausible denial their processing difficulty decreases or is completely eliminated. We investigated in six behavioral experiments whether the processing of negation is eased in a denial context triggered by discourse markers (e.g. "Contrary to expectations, John has/hasn't eaten the soup"). In order to investigate the necessary conditions for a context of plausible denial to reduce the processing cost of negation, we contrasted the processing of affirmative and negative sentences in minimal and extended denial and non-denial contexts (represented by either no context or a different type of context). We expected significantly longer response times (RTs) for negative sentences in comparison with affirmation in non-denial contexts and similar RTs for affirmative and negative sentences in denial contexts. The results from a sensibility judgement task (Experiment 1 and 2) and from a self-paced reading paradigm (Experiment 3 and 4) showed two robust main effects of context and polarity but no significant interaction between the two factors, suggesting that the processing of negative sentences was not facilitated in a context of minimal denial triggered solely by discourse markers. However, when the discourse markers were replaced with the explicit mention of the expectation to be denied and longer narratives used, the processing difficulty was eliminated specifically in the denial contexts (Experiment 5). Furthermore, when the discourse markers were used in longer narratives, a facilitation effect was also found (Experiment 6). All in all, the present findings suggest that, although negative sentences are felicitous in a context of plausible denial, the interplay of pragmatic factors like relevance or informativity is decisive in easing their processing difficulty.