(1) Background: Frontal fibrosing alopecia (FFA) is a scarring alopecia that predominantly affects postmenopausal women; (2) Methods: A retrospective, observational, single-center study was conducted in the Hospital General Universitario in Ciudad Real, Spain, including all patients diagnosed with FFA between 2010 and 2021; (3) Results: A total of 306 patients (296 women and 10 men) were included in our study. The mean age of onset was 59.5 years. The severity of this disease was evenly distributed between mild (147 patients) and severe (149 patients) forms. There was a positive, statistically significant, medium correlation between the severity of the disease and its time of progression. Moreover, hypothyroidism was present in 70 patients (22.9%) and classic signs of concomitant lichen planopilaris were observed in just 30 patients (9.8%), while other forms of lichen planus were uncommon. The estimated prevalence in our population is 0.15% and the incidence is 15.47 new cases per 100,000 inhabitants; (4) Conclusions: The time of progression was positively correlated with the severity of FFA. However, the presence of clinical signs, such as inflammatory trichoscopic signs, was not associated with the progression of this condition.