Aims: This study determined the effect of subcutaneous (SC) low molecular weight heparin (LMWH) injection in three different areas (abdomen, leg, and upper arm) after coolant spray application on pain, hematoma, and ecchymosis formation. Methods: The sample of this randomized controlled study consisted of 50 patients that were administered SC LMWH once a day. The SC injection occurred after applying coolant spray to the arm, leg, or abdominal region. The sample of this randomized controlled study consisted of 50 patients that were administered SC LMWH once a day. The SC injection occurred after applying coolant spray to the arm, leg, or abdominal region. Results: The study determined that there was no statistically significant difference in pain severity, hematoma, and ecchymoses between the regions of SC injection after coolant spray was applied (p>0.05). However, the highest average pain intensity directly and 15 minutes after the SC injection was in the leg region. Conclusion: SC injection after coolant spray application in three different regions led to the biggest hematoma in the abdominal region, the biggest ecchymosis in the arm region, and the lowest pain severity in the abdominal and arm regions. Key words: Coolant spray, ecchymosis, hematoma, pain, subcutaneous injection (SC).