As given by Our Lord to Saint Margaret Mary Alacoque
1. I will give them all the graces necessary for their state of life.
2. I will give peace in their families.
3. I will console them in all their troubles.
4. They shall find in My Heart an assured refuge during life and especially at the hour of death.
5. I will pour abundant blessings on all their undertakings.
6. Sinners shall find in My Heart the source and infinite ocean of mercy.
7. Tepid souls shall become fervent.
8. Fervent souls shall speedily rise to great perfection.
9. I will bless the homes in which the image of My Sacred Heart shall be exposed and honored.
10. I will give to priests the power to touch the most hardened hearts.
11. Those who propagate this devotion shall have their name written in My Heart, and it shall never be effaced.
12. I promise thee in the excess of the mercy of My Heart, that its all-powerful Love will grant to all those who shall receive Communion on the First Friday of Nine consecutive months the grace of final repentance; they shall not die under My displeasure, nor without receiving the Sacraments; My Heart shall be their assured refuge at that last hour.
For in depth explanation of these 12 promises, see Fr. Joseph McDonnell S.J.'s excellent reflections at www.DailyCatholic.org/2005pro.htm Archives.