>Hi,
>
>I have the following SP which is running very slowly:
>
>

CREATE PROCEDURE [dbo].[ManifestHeaderDelete]
>(
>	@man_number int
>)
>AS
>	SET NOCOUNT OFF;
>
>	delete [dbo].invoicedetails
>	from [dbo].invoicedetails
>	inner join invoices on ivd_invfk = inv_pk
>	inner join AirWayBills on inv_awbfk = awb_pk
>		  WHERE awb_manifestnumber = @man_number
>
>	delete [dbo].invoices
>	from [dbo].invoices
>	inner join AirWayBills on inv_awbfk = awb_pk
>		  WHERE awb_manifestnumber = @man_number
>
>	DELETE [dbo].[AirWayBillDetails]
>	 FROM [dbo].[AirWayBillDetails]
>	 inner join [dbo].[AirWayBills] on awd_awbfk = awb_pk
>		  WHERE awb_manifestnumber = @man_number
>
>
>	DELETE [dbo].[AirWayBills]
>	 FROM [dbo].[AirWayBills]
>		  WHERE awb_manifestnumber = @man_number
>
>
>	DELETE FROM [dbo].[ManifestHeader]
>	WHERE 
>		([man_number] = @man_number)

>
>Any advice on optimising this or should I use Cascading deletes based on referential integrity?

CASCADE DELETE sounds like the simplest solution for your case.

Otherwise I would select InvoiceId and InvoiceDetailsID into a temp table and then use it for other delete statements (which need to be in transaction, BTW).