This critical discourse analysis aimed to elucidate the different ideologies of the graffiti- writings of the generation Z students of New Bataan National High School, Davao de Oro, Philippines. From the analyzed linguistic corpora, the results revealed that the graffiti writings of high school students convey impermissible, very sensitive, grubby and bigoted expression of thoughts and feelings as graffitist. Eight major functions of the graffiti-writings were identified: expressing personal feelings, expressing resentment, expressing general insult, expressing sexual ideas, expressing self-glorification, quoting cartoon expression, and even a form of cheating. There were five themes extracted from the gathered linguistic corpora, these are:, sexual derogation, self-glorification, profanity and cursing. The result of this study is deemed significant for those practitioners of linguistics, education and language pedagogy.