Using a descriptive-analytical method, the present paper compares the concept of reprehensible blind partisanship in Shia and Sunni commentaries. Allamah Tabatabaii's Al- Mizan Commentary, Tabarsi's Majma' Al-Bayan Commentary, Makarem Shirazi's Nemooneh Commentary, Fakhr Razi's Mafatih Al-Qayb Commentary, Suyuti's Dorr Al-Manthur Commentary, Barusawi's Rooh Al-Bayan Commentary, and Zamakhshari's Al-Kashshaf Commentary are compared. The results show that all these commentators have unanimously condemned reprehensible blind partisanship and warned against its dangerous consequences and outcomes, such as having veil on the eyes, blasphemy, idolatry, becoming deaf and dumb and being in the darkness, associating with Arabs at the age of ignorance, following Satan, being captured in the fire of Hell, division, and loss of unity among Muslims. In order to be safe from these dire consequences and maintain unity among Muslims in particular, they should avoid aggravating differences which result in irrelevant biases, and use such factors as uprising for Allah, thinking, having piety, considering dire consequences of blind partisanship, directing and guiding reprehensible blind partisanships towards favorable and praiseworthy ones, being patient, submitting to truth, and raising the level of men's culture and faith to prevent the formation of or cure this vice.