Introduction: Osteoma is a benign tumour of the temporal bone and is very uncommon. Osteomas are reported very rarely from temporal bone but may occur in external auditory canal commonly as in other parts of body. Case report: A 22 year old female presented to ENT & HNS Department of DRRPGMC Kangra At Tanda with very hard swelling in left post auricular region diagnosed as osteoma. Under local anaesthesia complete excision complete excision up to cortical bone was done through post auricular approach. Further histopathology confirmed the diagnosis. Conclusion: While dealing with bony hard mastoid swellings, osteoma should always be kept in mind although they are rare. To avoid the recurrence of these swellings complete removal should be done by drilling till the normal cortical bone is reached. If while drilling we realize there is involvement of the mastoid air cell system then cortlcal mastoidectomy should be done which was not required in this case as there was not any involvement of mastoid air cells.