This study compare using of non surgical methosds included botulinum toxin injection and glyceryl tri nitrate 0.2% with surgical methods included fisserectomy with lateral internal sphinctrotomy in treatment of chronic anal fissure we found that using of surgical methods give results equal 100% after six month follow up while using of glycerial trinitrate 0.2% twice per day for 8 weeks the result was 70% healing rate while it was 75% in botulinum toxin injection we inject 20 unit of botulinum toxin in internal anal sphincter anterior after dilution of it in 50u saline .The complication was insignificant in three groups , incontinence was to flatus only and it disappear after three months follow up , we recommended using of lateral internal sphinctertomy as frist line in treatment of chronic anal fissure and using of chemical sphincterotomy in patient who unfit for surgery or refusing surgery.