On September 13, 1917, the Virgin of Fatima had announced to three little children the coming of Our Lady of Mount Carmel the next month. On October 13, during the closing of the cycle of apparitions, when the conversation of Lucy with Our Lady of the Rosary was finished, while the crowd contemplated the grandiose cosmic miracle, the three shepherds enjoyed several visions. They were given to admire in the sky three successive pictures, the last of which was Our Lady of Mount Carmel calling to mind the Glorious Mysteries of the Rosary. That same evening Lucy would relate her vision to Canon Formigao: At the end, the Virgin Who appeared to me seemed to me to be Our Lady of Mount Carmel.

At the end of the 40's, while conversing with three Carmelite priests, Father Donald O'Callagham, Father Albert Ward and Father Luis Gonzaga de Oliveira, Sister Maria-Lucia of the Immaculate Heart (known as Sister Lucy) recalled that the Blessed Virgin Mary wished that the devotion of the holy Scapular be propagated. If Our Lady, during Her last public apparition, had held it in Her hands, it was to urge us to wear it, quite like in the preceding apparitions, the presence of Her rosary had clearly manifested the wishes of Her Heart.

The messenger of Heaven also explained it to Father Howard Rafferty when the priest questioned her in the name of the Father General of the Carmelites, on October 15, 1950: Our Lady, Lucy told him, held the Scapular in Her hands because She wants us all to wear it.

The Brown Scapular is part of a religious habit belonging in its own right to the Carmelite order. Devotion for the Scapular of Our Lady of Mount Carmel was born in the 13th century when, after having been chased from Palestine by the Saracens, the Carmelite brothers encountered great difficulties in getting established in Europe and maintaining themselves there. In fact, it was in those tragic circumstances that Saint Simon Stock, elected Prior General of the Order in 1247, had, a few years later an apparition of the Blessed Virgin Mary presenting the Scapular to him as a sign of salvation for his brothers.

The scapular must consist of two pieces of brown cloth with one segment hanging on the wearer's chest, and the other hanging on his/her back. These pieces are joined by two straps or strings which overlap each shoulder—hence the word "scapular" (shoulder blade). Images sewn onto the Brown Scapular are unnecessary. In the past the scapular was required to be 100% wool but this is no longer required; the habits of the Carmelite religious are also now typically made of other, less expensive and more durable materials. It is normally worn under the clothes but not pinned to undergarments.

Because wool deteriorates rapidly in tropical climates, since 1910 those properly invested into a confraternity may wear a properly blessed scapular medal with the depiction of Jesus with his Sacred Heart on one side and Mary on the obverse. However, Pope Saint Pius X expressed his preference for the cloth scapular. Pope Benedict XV has also proclaimed the Church's strong preference for cloth to be worn rather than the medal.