AIM: To observe early clinical outcome with lens position adjustment following the implantable collamer lens (ICL) surgery. METHODS: Sixty patients were selected for this retrospective study. One eye from each patient received Toric ICL for astigmatism correction, and the other received non-astigmatic ICL surgery using horizontal position. Patients with higher postoperative arch height were selected, and their non-astigmatic eye clinical outcome were observed after ICL surgery at 1wk, 1, and 3mo. The clinical measurements included uncorrected visual acuity (UCVA), intraocular pressure (IOP), refractive state, corneal endothelium cell count, and arch height. Three months later, the ICL in each patient’s non-astigmatic eye was adjusted to the vertical from the horizontal position. The results were compared before and 1wk, 1, and 3mo after adjustment. RESULTS: UCVA and IOP were significantly reduced 1wk after position adjustment compared to 1wk after ICL implantation (P<0.05). The patients demonstrated significantly reduced arch height and corneal endothelium cell count 1wk, 1, and 3mo after adjusting position compared to 1wk, 1, and 3mo after ICL implantation (P<0.05). However, there was no significant difference in refraction between 1wk, 1, and 3mo after ICL implantation and position adjustment (P>0.05). CONCLUSION: Early positioning adjustment post-phakic ICL implantation can benefit patients with adjusted arch height or higher IOP. Despite the good clinical effects, the doctors should pay attention to the potential for adverse effects on UCVA and corneal endothelium cells following early position adjustment after posterior chamber phakic ICL implantation.