An evaluation of the mycological quality of the sand beaches of the Lisboa and Vale do Tejo coastal area in Portugal was undertaken in May-October 1994. The keratinolytic fungi, yeasts, potential pathogenic and allergic and/or environmental saprophytic fungi were analysed. The results for the yeast Candida were evaluated according to the “Proposed Guidelines for the Microbiological Quality of Sand” (Mendes et al., 1993). The data showed good/satisfactory quality of the sand beaches for the genus Candida. The results indicate that the allergic and/or environmental saprophytic fungi were the most common in sand beaches. The fungi Scopulariopsis and the yeast Candida could be used as specific indicator organisms of sand beaches quality. A new quality objective is introduced that will contribute to improve the sand beaches quality.