Hi,

This is my VF page code. But related list showing all contacts though I am using pageSize="1".

<apex:page standardController="Account">
       <apex:pageBlock>
       <apex:pageBlockSection>
       <apex:detail relatedList="false"/>
            <apex:relatedList list="Contacts" pageSize="1"/>
        </apex:pageBlockSection>
        </apex:pageBlock>
 </apex:page>