Annual growth rings in trees were thought to be due to sharp seasonal variations in the precipitation rates during the year. Accordingly temperate zone trees such as Egyptian trees were supposed to be away from this phenomenon. The temperate zones which are ment here are those of no sharp seasonal variations in the precipitation rates. The present study applied carbon-14 dating to prove that the growth rings in some Egyptian trees are annual. The method was based on the tropospheric measurements of C-14 during the period 1954–1981. C-14 exhibited a sharp peak resulting from the ever greater series of nuclear tests during 1963–1965. The presence of this peak for Egyptian trees proved that they form annual growth rings.