‘Stupidity’ is one of the topics in the field of behavioral abnormalities discussed by psychologists. Imam Ali (a.s.), who has made special efforts to correct behavioral abnormalities, has dealt with ‘stupidity’ in numerous cases in “Nahj al-Balagheh”. The present study seeks to examine the components of ‘stupidity’ from the perspective of “Nahj al-Balagheh”. It was carried out using the descriptive, analytic method and library study. The findings reveal that, from the viewpoint of Imam Ali (a.s), haste, laxity and unilateralism are signs of ‘stupidity’, and they can be used to spot people's stupidity. Imam Ali (a.s.) believes ‘stupidity’ causes some damages which include inability to recognize benefits, losses and poverty, including both material and spiritual instances. Imam Ali (a.s.) further holds ‘avoidance’ and ‘silence’, either of which is subject to its own circumstances and conditions, are the two strategies which can be used to evade and prevent the harms of stupidity. Imam (a.s.) strongly recommends avoiding stupid people, the opposite of which is making friends with them and receiving advice from them. ‘Silence’ is another solution which can be utilized when it is impossible to avoid stupid people. Regarding the therapeutic aspects of ‘stupidity’, it should be noted that although there is no explicit cure for ‘stupidity’ in the words of Imam Ali (a.s.), giving due consideration to the words collocating with ‘stupidity’ in Imam Ali's language reveals that ‘stupidity’ can be cured by making use of wisdom.