When the Opportunity is deleted then delete accounts and contacts of that opportunity
Trigger DeleteTrigger on Opportunity(after delete){ Map<Id,Opportunity> setopp=new Map<Id,Opportunity>(); for(Opportunity opp:Trigger.old){ setopp.put(opp.AccountId,opp); } List<Account> deletelist=new List<Account>(); List<Account> accountlist=[select Id,Name from Account where Id in:setopp.keyset()]; for(Account acc:accountlist){ deletelist.add(acc); } if(!deletelist.isEmpty() && deletelist.size()>0){ delete deletelist; } }