>Try this:
>

>declare @CenterLat float=47.7795
>declare @CenterLon float=-65.7191
>declare @SearchDistance float=250
>
>select *
>      from test
>where (latitude>=@CenterLat - @SearchDistance/111.0 and latitude<=@CenterLat + @SearchDistance/111.0)   AND
>      (longitude>=@CenterLon - @SearchDistance/111.0 and longitude<=@CenterLon + @SearchDistance/111.0) AND
>      3958.75586574 * ACOS(CASE WHEN SIN(@Latitude1/57.2957795130823) * SIN(@Latitude2/57.2957795130823) + 
>                                     COS(@Latitude1/57.2957795130823) * COS(@Latitude2/57.2957795130823) * COS(@Longitude2/57.2957795130823 - @Longitude1/57.2957795130823) < -1
>                                     THEN -1
>                                WHEN SIN(@Latitude1/57.2957795130823) * SIN(@Latitude2/57.2957795130823) + 
>                                     COS(@Latitude1/57.2957795130823) * COS(@Latitude2/57.2957795130823) * COS(@Longitude2/57.2957795130823 - @Longitude1/57.2957795130823) > 1
>                                     THEN 1
>                           ELSE 
>                                     SIN(@Latitude1/57.2957795130823) * SIN(@Latitude2/57.2957795130823) + 
>                                     COS(@Latitude1/57.2957795130823) * COS(@Latitude2/57.2957795130823) * COS(@Longitude2/57.2957795130823 - @Longitude1/57.2957795130823) < -1 END) <=@SearchDistance
>

>Just change @Latitude1, @Latitude2, @Longitude1, @Longitude2 to their real names (I'm too lazy right now :o))))

Thanks

With the parameters, it gives this:

DECLARE @CenterLat Float=47.7795
DECLARE @CenterLon Float=-65.7191
DECLARE @SearchDistance Float=250

SELECT * FROM Test
 WHERE (Latitude>=@CenterLat-@SearchDistance/111.0 AND Latitude<=@CenterLat+@SearchDistance/111.0) AND
  (Longitude>=@CenterLon-@SearchDistance/111.0 AND Longitude<=@CenterLon+@SearchDistance/111.0) AND
  3958.75586574*ACOS(
  CASE WHEN SIN(@CenterLat/57.2957795130823)*SIN(Latitude/57.2957795130823)+
            COS(@CenterLat/57.2957795130823)*COS(Latitude/57.2957795130823)*
            COS(Longitude/57.2957795130823-@CenterLon/57.2957795130823)<-1
            THEN -1
       WHEN SIN(@CenterLat/57.2957795130823)*SIN(Latitude/57.2957795130823)+
            COS(@CenterLat/57.2957795130823)*COS(Latitude/57.2957795130823)*
            COS(Longitude/57.2957795130823-@CenterLon/57.2957795130823)>1
            THEN 1
  END)<=@SearchDistance

However, it returns no record. So, there must be something with the syntax.

I also removed the last part as this was not in the original function.