The present study examines the influence of the influence of emotional valence of texts (positive, negative and neutral), on text comprehension and learning of the new words of 139 pupils of 5th grade. Eight stories were built in three versions—positive, negative and neutral. Each story included a pseudoword that appeared three times. The student had to detect pseudowords meaning from several clues inserted in the text. The purpose for reading did not focus attention to the learning of unknown words (incidental learning). After the reading, text comprehension and learning of unknown words were assessed (orthographic recognition task and definition task). Measures of receptive vocabulary, decoding, reading comprehension and verbal working memory were also administered. The text comprehension scores as well as those obtained at the definition task were significantly lower after the reading of positive texts rather than negative or neutral texts. The effect of text valence of new words learning has not been demonstrated. The results are interpreted in terms of distracting effect of the positive emotional content on text comprehension.