The current study analyzes the role of emoticons to disambiguate messages to detect the state of mood of the sender during a text-based communication. We used an affective congruence task where participants had to select if the sender was on a good or bad mood, reading text-messages describing emotional situations with a critical emoticon at the end. We manipulated the emotional valence of the emoticons, generating congruent and incongruent affective messages. Our focus was in the incongruous conditions to observe which information is used by the participants to detect emotions. Our results indicated that the emoticons did not always guide the disambiguation processes on text-based interactions. Specifically, we observed that the ambiguous messages (incongruent condition) with positive emoticons (negative text) and with negative emoticons (positive text), are selected more frequently as messages sent by persons with a negative state of mood. In addition, our results show that there are interactions between the valence of the emoticon and the valence of the preceding text. In spite of the tendency to select the negative mood, this tendency differs if we analyze the when the participants selected bad mood response.Furthermore, the congruence effect was observed only when emoticons were negative with slower RT in incongruent condition. Additionally, negative emoticons had slower RTs than positive emoticons. In the following we will further discuss some of these points