WORTH NOTING ON TV

* TUESDAY

Mrs. Piggle-Wiggle (Showtime, 9:35-10:35 p.m.): In Betty MacDonald's whimsical ``Mrs. Piggle-Wiggle'' books for kids, the eccentric title figure is renowned in her neighborhood for her cures for familiar childhood problems - the ``Fraidy Cat'' cure, for instance, or the ``Tattletale'' cure.

Now Jean Stapleton stars as Mrs. Piggle-Wiggle in a weekly live-action series of half-hour shows based on the MacDonald books and filmed entirely in New Zealand, home of one of the companies producing the show.

The series begins its regular schedule on Tuesday, June 14, at 7:30 p.m., but this hour-length prime-time preview gives adults a chance to see the first two shows: ``The Not Truthful Cure,'' starring Christopher Lloyd as the exaggeration-prone Grandpa Moohead, and ``The Pet Forgetters' Cure,'' starring Ed Begley Jr. and Joan Cusack in a story about a girl who's always forgetting to feed her pets.

The series is produced by Shelley Duvall, the actress who has also become known for launching children's shows. She appears in three of the later programs. * WEDNESDAY

NBA finals: (NBC, 9 p.m., EDT, to conclusion): The New York Knicks, Eastern Conference champions, face the Western Conference champs, the Houston Rockets, in Houston. It's the first in a best-of-seven series to determine the NBA chamions.

Great Performances (PBS, 9-11 p.m.): When it opened at the Sydney Opera House in 1990, the Australian Opera's updated version of ``La Boheme'' was a big hit with audiences and critics. Puccini's 1896 romance about young Bohemians in Paris had been pushed forward by director Baz Luhrmann to the 1950s - with espresso bars, neon lights, and references to Sartre.

That production proved the highest-grossing one in the company's history. It was revived last year, and in February was recorded at the Sydney Opera House by ``Great Performances'' to become the final program of the series' 21st season. It is performed in Italian with English subtitles.

Please check local listings for these programs.