Abstract: The study was undertaken in order to evaluate sperm morphology features of post-thawed semen of Tunisian Arab stallions. Forty two ejaculates was collected and frozen, during years 2009 and 2010, from 9 stallions aged between 9 to 24 years. After thawing, sperm morphology was studied after eosin-nigrosin stain. The percentages of abnormal head, mid piece, flagella, sperm with droplets and the total abnormal sperm were determined. Analysis of variance was carried out using SAS software. The results showed that all sperm morphology features varied among ejaculates within stallion and among stallions (p<0.01). The percentage of abnormal flagella and total abnormal sperm varied between young and old stallions (p<0.01). We concluded that freezing and thawing processes increased abnormal sperm that is due to cell alteration for old and young stallions, and consequently, the decrease of the quality of the thawed semen of Tunisian Arab stallions.