Background: Nasal obstruction after adenoidectomy and the need for second adenoidectomy operation i.e (Revision), put as under focus on nasal obstruction types after adenoidectomy. We should search and report the causes of nasal obstruction to improve outcomes of adenoidectomy. Objectives: To find out the causes of nasal obstruction after adenoidectomy. Patients and Methods: Comparative cross sectional study focus on causes of nasal obstruction after adenoidectomy operations which done in Al-FURATE general hospital, in a period between February 2015 to November 2017 to patients visit our outpatient clinic in determined days in a week. Eighty six paitents included in our study who complain from nasal obstruction and or decrease hearing and diagnosed clinically and by nasal endoscopy and imaging if needed to have adenoid enlargement, and planned for adenoidectomy. We entered data of each patient on questionnaire and follow up them in periods 1 week, 2 weeks, 1 month, 3months, 6months, 1year, to evaluate their nose, ear problems if founded. Results: Number of normal cases after adenoidectomy is 66 out of 86 i.e 76.74%, Nasal obstruction by adenoid regrowth is 8 out of 86 cases I,e 9.3% ,. while Nasal obstruction by inferior turbinate hypertrophy is 11 out of 86 i.e 12.79%, Males has the higher number of nasal obstruction by adenoid regrowth 62.5% of cases, while females has the higher number of nasal obstruction by inf. Turbinate hypertrophy 72.72%of cases. Nasal obstruction by adenoid regrowth is more common in (2-3 years) age group. Nasal obstruction by inferior turbinate hypertrophy is more common in age group (6-7 years). Conclusion 1- Most common cause of nasal obstruction after adenoidectomy is inferior turbinate hypertrophy. 2-Second most common cause of nasal obstruction after adenoidectomy is adenoid recurrence. 3- Males has the higher number of nasal obstruction by adenoid regrowth. 4- Nasal obstruction by adenoid regrowth is more common in (2-3 years) age group. 5- Nasal obstruction by inferior turbinate hypertrophy is more common in age group (6-7 years). Recommendations 1- We should try to decrease adenoidectomy operation as condition permits at least to after 4 years age. 2- Cases of adenoidectomy should follow up after operation as no any nasal obstruction mean adenoid recurrence. 3- Using endoscope during adenoidectomy may decrease recurrence. 4- We recommend more studies about nasal obstruction after adenoidectomy with more facilities