The purpose of this clinical study was to determine dental and skeletal effects of non-compliance pendulum appliance (PA) in upper molar distalization. The material consisted of 11 Class II patients (6 girls, 5 boys), mean age 14.8±1.8 years, with moderate space deficiency in the upper arch; treated with the PA for bilateral distalization of the upper first molars. The PA was worn till the super Class I relationship was obtained. The mean treatment duration was 5.90 months (SD=1.87 months). Lateral cephalometric head films were taken before and at the end of molar distalization; and 22 linear and angular measurements were done to determine skeletal and dental changes. The amount of horizontal movement of molar and incisor teeth was evaluated from superimposition of tracings on the PTV plane; whereas the vertical movement was evaluated from superimposition on the palatal plane. Angular changes were analyzed in relation to SN plane. Non-parametric Wilcoxon test was used to assess significant changes. Significant changes were as follows: Upper first and second molars were moved distally (mean= 2.77 and 2.10 mm, respectively) with a mean distal tipping of 5.77° and 7.50°. The mean anterior movement of the upper incisor was 1.91 mm without tipping. As, nearly same amount of anterior movement was seen in lower molar (2.00 mm) and incisor (1.17mm) due to normal growth, no significant change was observed in overjet. Significant skeletal change was observed only in the anterior lower face height with increasing of a 0.81mm. The results of this study showed that PA is an effective appliance in molar distalization with an advantage of independence on patient compliance. In addition; side effects, such as significant distal tipping of the molars, need to be taken into consideration in treatment planning.