IMRT delivery techniques (Sliding Window & Multiple Static Segments) for head & neck cancer cases were evaluated in this study. Planning target volume (PTV) coverage, Conformity Index, Homogeneity Index, doses to organ at risks (OARs) and PQI are considered as evaluation parameters. Detail about the parameters used for comparison is given in section 2.9 of materials and methods. While comparing techniques, it was made sure that target coverage and doses to OARs stayed within the constraints given by International Commission on Radiation Units and Measurements guidelines (ICRU). Dosimetric comparison of Dynamic intensity modulated radiotherapy and Static Intensity modulated radiotherapy using seven and nine fields was done in this study. Twenty patients i.e. 15 patients of NPC and 5 patients of larynx were randomly selected. All treatment plans were created by SIB (Simultaneous Integrated Boost) technique with a prescribed dose of 66.9 Gy within 33 fractions. After CT simulation, delineation of planning target volume (PTV) and organs at risk (OARs) was done by oncologist. Brainstem, spinal cord, and parotid glands were contoured as OARs. Four different plans (7FSW, 7FSS, 9FSW, and 9FSS) were created for each patient using Eclipse treatment planning system. The quality of IMRT plans has been significantly affected by the number of different techniques used in this study. In NPC patients, the 9F-IMRT techniques (SW and SS) produced an appropriate homogeneous dose of PTVs and resulted in pronounced sparing of nearby OARs from 7F-IMRT (SW and SS). This study shows that the results relating to PTV coverage are identical between SW and SS IMRT but in case of beam angles, 9-fields showed better PTVs coverage than 7-fields. PTV has a major contribution to the conformity index, homogeneity index, PQI, and D95%. PTV coverage and low doses to OARs were obtained better in Static segment than sliding window. In case of 7 and 9 beam angles, nine fields showed good results than seven fields.