  We report the discovery of RV Tauri stars in the Large Magellanic Cloud. In
light and colour curve behaviour, the RV Tauri stars appear to be a direct
extension of the type II Cepheids to longer periods. A single period-
luminosity-colour relationship is seen to describe both the type II Cepheids
and the RV Tauri stars in the LMC. We derive the relation: $V_{\circ} = 17.89
(\pm 0.20) - 2.95 (\pm 0.12) \log_{10}P + 5.49 (\pm 0.35) \bar{(V-R)_{\circ}}$,
valid for type II Cepheids and RV Tauri stars in the period range $0.9 <
\log_{10}P < 1.75$. Assuming a distance modulus to the Large Magellanic Cloud
of 18.5, the relation in terms of the absolute luminosities becomes: $M_{V} =
-0.61 (\pm 0.20) - 2.95 (\pm 0.12) \log_{10}P + 5.49 (\pm 0.35)
\bar{(V-R)_{\circ}}$.
