Purpose The objective of this study was to investigate whether cryotherapy is effective in reducing pain, opioid consumption, and length of stay (LOS) in hospital following total knee arthroplasty (TKA). Methods This prospective cohort study included 191 consecutive patients who underwent TKA without having access to cryotherapy, followed by 193 consecutive patients who underwent TKA and received automated cryotherapy as part of the recovery phase. All patients had their surgical procedures performed by the same surgeons and received post-operative care by the same nursing, medical, and physiotherapy team. The pain score using the visual analog scale (VAS)and the amount of opioid used on the first three post-operative days were recorded along with the length of hospital stay. Results There was no difference in baseline characteristics between the two groups. The use of cryotherapy was associated with a reduced pain score on all three days compared to when cryotherapy was not used: Day 1 pain score was 5.2 versus 6.1 (p < 0.01), Day 2 was 3.6 versus 4.8 (p = 0.03), and Day 3 was 2.8 versus 3.8 (p < 0.01). Cryotherapy was also associated with a significant reduction in analgesia consumption on all three days. The median amount of Oramorph used on all three days in the cryotherapy group was 15.0 mg compared to 40.0 mg in the control arm (p < 0.01). Additionally, the LOS was shorter in the cryotherapy group, with a mean of 3.86 days versus 4.20 days in the control group (p = 0.02). Conclusion The use of cryotherapy following TKA was associated with decreased pain and opioid consumption along with a reduced time to hospital discharge compared to when no cryotherapy was used.