'Sequential Plastic Aligner' treatment is an exciting development in the field of orthodontics both for patients and clinicians. However aligners are not as simple to use as it may seem at first glance. As with most dental treatment, success or failure depends very much on case selection and treatment planning. These appliances offer great advantage of esthetics, oral hygiene, minimal chair time and can be considered as a good treatment option for selected cases with mild malocclusions. Current systems have limitations with current technology to achieve space closure with proper tip and torque to produce root parallelism and esthetic crown angulations in severe malocclusions which require extraction of premolars. Future developments in technique and technology may overcome these limitations and therefore enhance their utility for the treatment of more severe forms of malocclusions.