<p>The aim of this study is to investigate whether the levels of sexual excitement seeking, impulsivity, relationship satisfaction and infidelity differ in heterosexual and LGBT individuals. A total of 250 people, 147 heterosexual individuals and 103 LGBT individuals, participated in the study. There was a statistical difference between heterosexual and LGBT individuals in terms of sexual sensation seeking scale scores. Heterosexual individuals scored higher on the sexual sensation seeking scale than LGBT individuals. LGBT individuals had statistically significantly higher relationship assessment scale scores than heterosexual individuals. There is no statistically significant difference between the scores of heterosexual and LGBT individuals from Barratt Impulsivity Scale total, non-planning, motor impulsivity and attention impulsivity. LGBT participants’ scores on the Sexual Sensation Seeking Scale were statistically significant and positive predictors of the Causes of Infidelity Tendency Scale scores. Sexual Sensation Seeking Scale had a mediating role in the relationship between Barratt Impulsivity Scale scores and Causes of Infidelity Tendency Scale scores of heterosexual individuals. The Sexual Sensation Seeking Scale did not have a mediating role in the relationship between the Barratt Impulsivity Scale scores of LGBT individuals and the Causes of Infidelity Tendency Scale scores. As a conclusion, it is adviced that the impulsivity and relationship satisfaction should be searched for LGBT and heterosexual people seperately.</p>