The present study aims to investigate pejoration in Egyptian Arabic and its causes through employing historical semantic and sociolinguistic approach for pursuing in-depth investigations of pejoration in Egyptian Arabic. The lexical items examined in the study are divided into moral lexical items and neutral lexical items. The study has found out that pejoration in Egyptian Arabic has been shown to be high in lexical items charged with sexual connotations. Moral items are more prone to pejoration than neutral lexical items. Nouns are more prone to pejoration than adjectives and verbs. In addition, pejoration results into a remarkable gap between Modern Standard Arabic and Egyptian colloquialism. The study concludes that there may be a mutual relationship between morality and pejoration in the Arabic language, which requires further investigation and research.Keywords: Sociolinguistic, historical semantic, MSA, pejoration, semantic change, vernacular speech.