Primary focal hyperhidrosis affects 1-3% of the worldwide population. It starts at puberty and has a familiar component in 30-65% of cases. Excessive prespiration has personal, social and occupational implications. Generally, it is clinically diagnosed, without complementary tests needed Aluminum Chloride (AC) appears as a first line of treatment It has good results for axillary, palmar and plantar focal hyperhidrosis. It is less effective for craniofacial hyperhidrosis. Local irritation is the main drawback but it is a treatable complication. AC is an effective and widely used treatment for primary focal hyperhidrosis.