Determining whether a volcanic area exhibits seismicity and identifying the rates and types of signals that are occurring are important diagnostic tools for assessing volcanic unrest. We present an analysis of seismicity recorded with a single available sensor, and some parameters that we can determine from it, to demonstrate the level of unrest and encourage future studies about the nature of Mexico's Ceboruco Volcano and its hazards. With a single station it is possible to determine whether there is seismic activity occurring near the volcano and to study some important aspects related to the seismic signals detected. In these circumstances, or course, conclusions should be drawn cautiously because of data limitations. In this article we describe the seismicity detected at Ceboruco Volcano with an autonomous three-component, short-period seismograph station (sensor with a sampling rate of 125 samples/s), which first started operating in 1996. For our study we used the best available data recorded during 2003–2008. This paper contains the first results published on seismicity at Ceboruco and should serve as a basis to foster further research and enhance monitoring activity at this important volcano. Ceboruco Volcano (104.5°W, 21.1°N, 2,280 m above sea level or m.a.s.l., Figure 1) in the state of Nayarit, Mexico, is an historically active volcano near the western end of the Mexican volcanic belt (Simkin and Siebert 1994). During the last 1,000 years, Ceboruco has produced at least eight eruptions (Nelson 1980), including caldera-forming explosive events and emplacement of thick lava flows. At least four stages of activity, herein named stages I through IV, have been suggested from studies of explosiveness and compositional variations of erupted products (Demant 1979; Nelson 1986; Suarez-Plascencia 1998):