Assalam u alykum, We are going to hold a open day for non muslims at our masjid, which will have posters about islam and activities for kids etc. With imam to answer questions and knowledgable brothers doing tours. What I wanted to know if its permissible to muslim women to attend this considereing they will not all be dressed appropriately and there will be muslim men there.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

There is no doubt that inviting people to Islam which you are intending to do is one of the best good deeds as Allaah Says (what means): {And who is better in speech than one who invites to Allaah and does righteousness and says, ''Indeed, I am of the Muslims''.}[Quran 41:33]

Indeed, Allaah ordered us to call people to Islam as He Says (what means): {Invite to the way of your Lord with wisdom and good instruction, and argue with them in a way that is best.}[Quran 16:125] However, this is not a sound excuse for women to mix with men or for women to attend while they are not properly dressed. In fact, it is not a necessity or a need for making Da’wah that this prohibition takes place.

Therefore, it is not permissible for a Muslim woman to go out of her home – to the gathering that you will organize or to any other gathering – unless she wears the Hijab. Moreover, it is not permissible for you to allow the mixing of men and women in a way that may lead to temptation.

For more benefit on the prohibition of mixing between men and women even when doing Da’wah, please refer to Fatwa 84281, and for more benefit on the conditions of Hijab, please refer to Fatwa 83702, and to Fataawa 82236 and 83119 on the permissibility of a non-Muslim entering the mosque for a need, like for calling him to Islam.

Allaah Knows best.