Abstract Background:  Botulinum  toxin type A injection  has become a worldwide  leading  method for treating facial rhytides specially in women. Authors still debate whether or not regular administration of the toxin may delay or prevent kinetic horizontal forehead lines from changing their nature to static ones and hence the need for further interventions includingfacial cosmetic surgery. This study was performed to analyze the relationship between regular administrations of Botulinum toxin type A injection and the change in nature ofhorizontalforehead lines. Methods: Forty female patients, whose ages ranged from 35 to 45 years, were divided into two groups of twenty each. Group A included females who had regular administration (2-3 times annually) of Botulinum toxin type A to treat horizontal forehead lines. Group B included twenty females who infrequently  (once every 12-18  months)  had Botulinum  toxin type A injection. Changes  in nature of the horizontal  forehead lines were compared  between the two groups, according to the Carruther 's five grade scale for forehead wrinkles established in 2008. Results:  Eighty five percent of Group A patients who had regular Botulinum toxin type A injections,  showed no change to their forehead lines after five years, and  only 15 % of the group showed one grade change. On the contrary, five years later, 80 %of group B females showed change in the nature of their forehead wrinkles one or two grades more, according to the Carruthers scale of forehead rhytides. Conclusion: Regular administration of Botulinum toxin type A during its effective period of action (4 to 6 months), two or three times per year, prevents progression of forehead horizontal wrinkles from changing their kinetic nature over a period of five years.