An assist grip attachment structure in which an assist grip is attached to a vehicle body-side attachment portion (14, 60), the assist grip is supported with prescribed rigidity by the vehicle body-side attachment portion when a tensile load (Fex) in a direction in which the assist grip is pulled toward an inside of a vehicle cabin is applied to the assist grip, and an impact of a pressing load (Fpr) is absorbed through deformation of the vehicle body-side attachment portion when the pressing load is applied to the assist grip from the inside of the vehicle cabin, the assist grip attachment structure characterized by comprising: a low-rigidity portion (34, 64a-64d) provided in the vehicle body-side attachment portion; a high-rigidity portion (36, 66a-66d) provided in the vehicle body-side attachment portion and having rigidity higher than rigidity of the low-rigidity portion; a pressing-side engagement portion that is fixedly fitted to the assist grip, that is engaged with the low-rigidity portion, and that presses and deforms the low-rigidity portion from the inside of the vehicle cabin when the pressing load is applied to the assist grip; and a tension-side engagement portion that is fixedly fitted to the assist grip, and that is engaged with the high-rigidity portion from a side opposite to the inside of the vehicle cabin when the tensile load is applied to the assist grip, the vehicle body-side attachment portion having an attachment plate portion having an engagement hole in which an attachment end portion of the assist grip is inserted from the inside of the vehicle cabin and is engaged, and the attachment plate portion further having cuts (32, 62a-62d) formed along the engagement hole of the attachment plate portion in a vicinity of the engagement hole, a portion located inward of the cuts being used as the low-rigidity portion, and a portion located outward of the cuts being used as the high-rigidity portion. a low-rigidity portion (34, 64a-64d) provided in the vehicle body-side attachment portion; a high-rigidity portion (36, 66a-66d) provided in the vehicle body-side attachment portion and having rigidity higher than rigidity of the low-rigidity portion; a pressing-side engagement portion that is fixedly fitted to the assist grip, that is engaged with the low-rigidity portion, and that presses and deforms the low-rigidity portion from the inside of the vehicle cabin when the pressing load is applied to the assist grip; and a tension-side engagement portion that is fixedly fitted to the assist grip, and that is engaged with the high-rigidity portion from a side opposite to the inside of the vehicle cabin when the tensile load is applied to the assist grip, the vehicle body-side attachment portion having an attachment plate portion having an engagement hole in which an attachment end portion of the assist grip is inserted from the inside of the vehicle cabin and is engaged, and the attachment plate portion further having cuts (32, 62a-62d) formed along the engagement hole of the attachment plate portion in a vicinity of the engagement hole, a portion located inward of the cuts being used as the low-rigidity portion, and a portion located outward of the cuts being used as the high-rigidity portion.