Activity › Forums › Salesforce® Discussions › How to create Rollup summary field on lookup relation in Salesforce? Tagged: Lookup Relationship, Master Detail Relationship, Rollup Summary Field, Salesforce Relationships Salesforce® Discussions How to create Rollup summary field on lookup relation in Salesforce? Posted by Aman on September 23, 2018 at 7:22 AM How to create Rollup summary field on lookup relation in Salesforce? shariq replied 7 years, 7 months ago 2 Members · 1 Reply Lookup RelationshipMaster Detail RelationshipRollup Summary FieldSalesforce Relationships 1 Reply shariq Member September 23, 2018 at 7:22 AM Not possible. Roll-up summary is enabled for only Master –Detail relationship. Log In to reply. Public All Members My Connections Only Me PublicAll MembersMy ConnectionsOnly Me Public All Members My Connections Only Me