Introduction. Our work aimed at reporting the occurrence of an anomaly in pineapple fruit in the state of Acre. Materials and methods. Fruit observations were accomplished in the pineapple experimental area of Embrapa Acre, in Rio Branco, AC, Brazil, from 1987 to 1998. Results and discussion. Typical symptoms of the studied anomaly were observed in the varieties Pérola, Quinari and Abacaxi de Tarauacá: an early yellowing of the skin of the superior half of the fruit was noted, while the skin of the lower half retained its green color, as if the fruit was not ripe yet. In the interior of the fruit, a cavity or crack was present in the area of the main axis. No plant pathogenic organism was isolated from the cavity inside the fruits. Also, it was not possible to relate the occurrence of abnormal fruits with climatic factors, considering that fruit with normal ripening of the same varieties were picked at about the same time from nearby pineapple plants. The occurrence of fruit with abnormal ripening was not observed in other pineapple varieties, such as Rio Branco, Cabeça-de-Onça and SNG-3, cultivated in Acre. Conclusions. It was not possible to associate the anomaly with biotic or non-biotic factors. Thus, it could be of physiological cause.