Background: Although contrast-enhanced T1-weighted MR imaging is the standard of reference for diagnosing tumour in the cerebellopontine angle (CPA), high-resolution T2-weighted imaging may show more details of the seventh and eighth cranial nerve branches, resulting in more accurate tumour volume measurements. The Aim of Study: Was to evaluate the value of diagnostic accuracy of an unenhanced MR imaging protocol using unenhanced axial 3D constructive interference in steady state (CISS) in detection of small internal auditory canal lesions (IAC). Patients and Methods: cross-sectional study carried out over a period from April 2018 to February 2019 in the MRI department of Al-Imamain Al-Kadhemain medical city, included 38 patients (76 internal auditory canals), whom presentation with clinical features of (sensorineural hearing loss, tinnitus or vertigo) with suspicion of IAC lesions, sent by specialist after clinical examination. All patients were examined with axial T1WI, axial T2WI, coronal FLAIR, axial 3D-CISS sequence for evaluate its accuracy in detecting abnormalities of the CPA, IAC and inner ear. Each sequence assessed carefully for detection of any lesion within IAC, inner ear and CPA cistern, the statistical analysis is assessed for the sensitivity, specificity and accuracy. Results: 38 patients (76 IACs /CPA cisterns) met the inclusion criteria, included 18 (47.4 %) patients with radiological evidence of IACs /CPA cistern lesions, 20 (52.6%) patients without lesions, considered as the control group which confirmed by IAC/CPA cistern routine sequences in addition to confirmation by 3D-CISS sequence. Thus 76 IACs are examined 18 with lesions, 58 IACs without significant pathology. The sensitivity, specificity and accuracy of 3D CISS sequence and axial T2WI are estimated separately and both together. 9 lesions (50 %) found intracanalicular 4 fundal (22.2%) and 5 (27 %) within CPA cistern. The number of lesions in diseased group showing true positive results by 3D-CISS sequence were 17 (94.4 %) of detected lesions while one lesion (5.6%) showing false negative result by CISS sequence because it was arachnoid cyst not clearly identified. While the number of lesions in control group showing false positive results were 2 (10.0 %) due to volume averaging artifact, the true negative lesions were 18 (90.0 %), (P-value 0.0001). The number of lesions in diseased group showing true positive results by T2WI sequence were 15 (83.3%) of detected lesions while 3 lesions showing false negative result by T2WI sequence representing (16.7%). Whereas the number of lesions in control group showing false positive results were 4 (20.0%) due to artifact, the true negative lesions were 16 representing (80.0%) (P-value 0.0001). The Sensitivity of axial 3D-CISS sequence was (94.4%), specificity (90%) and accuracy (92.1%). The Sensitivity of axial T2WI sequence was (83.3%), specificity (80%) and accuracy (81.6%). Conclusion: 3D CISS sequence is supply high topographic resolution, with high contrast to noise ratio that highly beneficial for defining the exact location of the lesion and follow the vascular structures and nerves with clarity. It shows high sensitivity and specificity in detection of lesions of IACs and CPA cistern. Elderly patients and patients with allergy to gadolinium contrast agent can get benefit from using a 3D CISS sequence as screening and diagnostic tools and for follow up.