Background: Peripheral intravenous catheter (PIVC) insertion is usually technically easy and causes only mild discomfort for patients. However it could become difficult and complicated in certain situations, mainly in patients receiving chemotherapy due to the recurrent exposure to venous catheterization, in addition to the damaging effects of chemotherapeutic drugs on the vessel wall. Thus, an easy, available, and fast method is required to facilitate the venous cannula insertion. Application of heat at the PIVC insertion site is one of the beneficial methods that increase the vein visualization consequently improves the insertion of PIVC. Aim: to evaluate the effect of dry heat application on PIVC insertion parameters, and discomfort among patients undergoing chemotherapy. Design: A quasi experimental pre-posttest nonequivalent groups design was utilized. Setting: the study was carried out in the oncology department at EL-Manial University Hospitals-Egypt. Sample: A purposive sample of 70 adult male and female patients divided into two equal groups, study and control (35 patients each). Tools: four tools were utilized, Patient's demographic and Medical background data form (tool I); Vein Assessment Scale (tool II); Two questions related to the length of the procedure and number of attempts or pricks (tool III); and Discomfort visual analogue scale (tool IV). Results: the study findings indicated that there was a statistical difference between study and control groups in relation to vein assessment scores, insertion duration, and number of attempts (p- value = 0.000) for all parameters after intervention. Moreover, there was a statistical significant difference in patients' discomfort level total mean scores between the study and control groups (p- value=0.000) after intervention as well. Conclusion: study concluded that dry heat application at the IV insertion site increased vein visibility, reduced the insertion time, reduced the number of pricks, and reduced discomfort among patients receiving chemotherapy. Recommendation: the application of local heating at the insertion site for chemotherapy patients is an effective, easy, and economical way, therefore it is recommended before IV cannulation to improve patients' satisfaction and the quality of care provided.