This paper contains a thorough description of significant role that ethical subjectivism plays within gender discussions. Namely, we can notice that the concept of gender identity is nowadays often discussed at the middle of important social discussions. The main reason for this can be found within the perception of gender identity as something fluid and subjective which has enabled it to impose itself among the public as a subversive topic and a reason why numerous polemics are being conducted. This explains the need for a detailed analysis of the relationship between use of ethical subjectivism during gender identification and the interpretation of the fundamental items that make up gender identity. The aim of this paper is to present the exact definitions of ethical subjectivism, gender identity, and the role which ethical subjectivism plays in defining gender, which turns out to be one of the essential components of gender identity. Moreover, this paper brings different opinions on the mentioned topic. The view which is particularly emphasized claims that defining gender, by using ethical subjectivism, is in the direct contrast with biological sex, which is defined and supported by objective factors. Consequently, we can see that the gender identity consists of several elements and that it is necessary to analyze the significance of their interrelationship and the way in which they construct the overall identity of a person. Furthermore, the importance of this topic should be emphasized because its content extends to many scientific and philosophical disciplines, among which we can highlight linguistics, semantics, metaphysics, logic, sociology, medicine, etc. With this in mind, it can be concluded that the use of ethical subjectivism during gender identification has proven to be a topic that should be studied with a dose of constructive criticism due to the way it impacts the way we acquire knowledge. As well as the foundations of knowledge we have about ourselves and the reality in which we exist.