In this study, experiments were done to see the effects of different initial live weights (light and heavy) and sex (male and female) on the fattening performance and economic analysis of fat-tailed lambs (traditional names is Gicik) in pasture feeding. According to result, daily and total live weight gains in light group were 182 g and 12.74 kg, respectively. The values for heavy group were 138 g and 9.66 kg. As for different sex, the male lambs found to get more daily and total live weight gain (134.29 g and 9.40 kg) than the females. Male lambs and lambs with low initial live weight have more advantage than others in terms of net profit. As a result of providing more live weight gain and profit, the light and male lambs can be suggested to the producers who want to breed.