>Try
>

>SELECT maintable.pk,
>		(select COUNT(*) from childtable1 where pk = maintable.pk) as a,
>		(select COUNT(*) from childtable2 where pk = maintable.pk) as b,
>		(select COUNT(*) from childtable3 where pk = maintable.pk) as c,
>		(select COUNT(*) from childtable4 where pk = maintable.pk) as d,
>		(select COUNT(*) from childtable5 where pk = maintable.pk) as e,
>		(select COUNT(*) from childtable6 where pk = maintable.pk) as f
>	from maintable
>	where maintable.pk = @lnPK
>

Thanks Sergey. This query is so much better and simpler than the tangled mess I was writing.