Cryotherapy is one of the simplest and oldest therapeutic techniques used in physical rehabilitation; it involves the cooling of a target tissue to promote a decrease in local metabolism and to reduce injury symptoms. The present study aimed to assess the effectiveness of cryotherapy on pain relief among patients receiving intramuscular injection Research design: A quasi-experimental research design was utilized in this study. Setting: the study was carried out in medical departments at the Benha University Hospital. subjects:A convenience sample of (80) adult patients with vitamins intramuscular injection and divided into two equal groups: (control group who not received intramuscular injection and study group who received intramuscular injection 40 for each). Tools for data collection: Three tools were used in this study; Tool 1: A structure interview assessment sheet which included three parts; it was designed to assess patient demographic data and health data ; Part I: Patients’ sociodemographic characteristics. Part II: Health data assessment. Part III: Questions related to factors that increase the severity of pain. Tool 2: Pain assessment sheet included two parts; Part I-Checklist of nonverbal pain indicators to assess the patients' pain level regarding intramuscular injection and the application of cryotherapy, Part II- Verbal pain assessment sheet to assess character of pain result from intramuscular injection and cryotherapy. Tool 3: Universal pain assessment scale to assess pain intensity marked by word descriptors. Results: Showed that highly significant difference regarding pain intensity between control & study post groups and between study pre group &study post group immediately and after ten minute .Conclusion: All the study group patients had positive effect of application of cryotherapy in pain relief; where the study group express lower pain intensity than control group during intramuscular injection, these results justified the research hypothesis of the present study. Recommendations: The study recommended that an instruction about the application of cryotherapy and its effect on minimizing the pain should be conducted for nursing staff and replication the current study on a large sample of different age groups of patients.