Our remarks

Audemars Piguet Perpetual Calendar Ref. 25657BA – 18k Yellow Gold – Mother-of-Pearl Dial – Moonphase – Box & Papers – 1988 – Excellent Condition —Rare Example

We are delighted to offer this exquisite and highly collectible Audemars Piguet Perpetual Calendar Reference 25657BA, crafted in solid 18k yellow gold and featuring a breathtaking factory Mother-of-Pearl dial — one of the most elegant and desirable configurations within the maison’s classical perpetual calendar line.

Dating to 1988, this example belongs to the early generation of ultra-thin Audemars Piguet perpetual calendars that defined the brand’s aesthetic and technical direction through the 1980s and 1990s. These pieces — built around the celebrated extra-flat Caliber 2120/2800 — represent an era in which AP’s mastery of discreet, high-complication watchmaking reached its apex.

The Mother-of-Pearl dial is spectacular, displaying natural iridescent hues that shift between cream, gold, rose, and soft blue depending on the light. The layout is beautifully balanced: day at 9 o’clock, date at 3, month and leap year at 12, and a richly detailed moonphase display at 6. Slim gold feuille hands and applied indices float effortlessly above the luminous dial surface, creating an impression of refined celestial harmony.

The 18k yellow gold case, with its slim profile and polished bezel, remains in excellent condition and retains the quiet elegance that characterizes AP’s pre-Royal Oak complication pieces. The watch wears with remarkable lightness, underscoring the technical sophistication of its ultra-thin automatic movement.

Inside beats the legendary Caliber 2120/2800 — widely regarded as one of the greatest ultra-thin perpetual calendar movements ever produced. Its architecture, refined finishing, and mechanical reliability have made it an enduring reference point in haute horlogerie.

This full set includes:

- Original Audemars Piguet presentation box

- Original warranty papers (1988)

- 18k yellow gold case and matching folding clasp

- Excellent overall condition throughout

Early Audemars Piguet perpetual calendars with Mother-of-Pearl dials have become increasingly sought after, combining mechanical poetry, neo-vintage charm, and true rarity — and well-preserved full sets from the late 1980s are exceptionally hard to find today.

„What a rare and beautiful early piece — the ultra-thin movement, the warmth of yellow gold, and the iridescent beauty of the MOP dial make the Ref. 25657BA one of the most captivating neo-vintage complications in the entire Audemars Piguet lineage.”