The population dynamics of the agave scale, Acutaspis agavis (Townsend and Cockerell), on Agave tequilana Weber var. azul were studied in the state of Guanajuato, Mexico. Weekly samples were taken of plants to monitor for the presence of scales and to quantify the different developmental stages of the diaspid, together with its parasitoids and predators. Results showed some reproductive activity throughout the year, with two peaks in the abundance of eggs and first-instar nymphs in May and September, suggesting two generations annually of scales occur in the study area. First-instar nymphs within scales and “crawlers” increased in abundance from April through May and from August through early October, with these differences generally being significantly greater than during winter and mid-summer months. The predatory coccinellid Chilocorus cacti fed on the scale and increased in abundance from August to December when eggs and young scales were most abundant. Parasitism by Aphytis spp. occurred throughout the year. Data presented here indicate that the stages of the agave scale most susceptible to chemical control (first instars, or crawlers) were significantly more abundant in May (first generation) and September (second generation). This indicates that the development of an integrated pest management program to control A. agavis in tequila agave plantations in the region should focus control tactics on these periods of the year.