(1) Background: Intrauterine insemination (IUI) is considered a first-line procedure for infertile or hypo-fertile couples among assisted reproductive techniques. In our retrospective study, we identified variables associated with a successful IUI and the probability of obtaining a pregnancy. This is useful to identify couples with a good chance of obtaining a pregnancy through an IUI procedure (2) Methods: The study was conducted at a university-level fertility clinic in Oradea, Romania. Patients eligible to participate in the study were infertile couples who underwent IUI treatment in the interval between January 2015 and October 2020. (3) Results: In our study, we found that duration of infertility, couple age, endometrium thickness, sperm concentration, and motility are important factors in determining the outcome of IUI. Several demographics were measured for each couple including maternal and paternal age, the type and duration of infertility, the number of procedures, the type of ovarian stimulation, number of follicles, endometrial thickness, the type and day of ovulation induction, associated pathology, tubal patency, and pre/post washes sperm count and progressive sperm motility. (4) Conclusions: Fertility prediction studies are necessary, and an individualized prognostic score should be applied for each couple for tailoring their expectations and better counseling.