Aspects of distribution and population dynamics were assessed in two rock shrimp species of the genus Sicyonia. Samples were obtained by sea bottom trawling in depths from 50 to 460 m during two research cruises on board the B/I BIP XII in the Gulf of California, Mexico. Taxonomic identification of specimens was performed; measurements of individual length and weight data were taken to obtain biometric relationships and length frequencies. Growth parameter estimations were performed adjusting the von Bertalanffy growth model (VBGM), and the recruitment pattern was obtained by the ELEFAN II method. Longevity was estimated with the Taylor equation, natural mortality with six different models, and length at first maturity by the logistic model. A total of 67 fishing trawls were monitored, and 1,330 specimens were caught (65% S. ingentis; 35% S. penicillata) in the depth range from 124 to 338 m. Sex ratio (F:M) was 1.0:1.6 for both species; weight and length relationships (both sexes) showed an isometric growth for S. ingentis and positive allometric growth for S. penicillata. Growth parameters and longevity values were moderate (1.71 and 1.81 years) with age at first maturity around six months for both species. The recruitment pattern showed continuous periods all year long, with a notable peak from November to May. Average natural mortality was 2.47 for S. ingentis and 2.35 for S. penicillata. Distribution and population dynamics information reported in this study for these two shrimp species should be considered as base knowledge in subsequent studies on fisheries management in the Gulf of California.Distribution and population dynamics aspects were assessed in two Rock shrimp species of the genus Sicyonia. Two research cruises were performed on board B/R BIP XII in the Gulf of California; specimens were sampled through sea bottom trawling in depths from 50 to 460 m. Taxonomic identification of specimens was performed; individual length and weight data were taken to obtain biometrics relationships and length frequencies. Growth parameters estimations were done adjusting the von Bertalanffy growth model (VBGM) while the recruitment pattern was obtained by the ELEFAN II method. Longevity was estimated by means of the Taylor equation, natural mortality with six different models, and length at first maturity by the Logistics model. A total of 67 throws were monitored, and 1330 organisms were caught (65% S. ingentis; 35% S. penicillata) in the range from 124 to 338 m in depth. Sex proportion (male-female) was approximately 1.0:1.6 for both species; weight and length relationships showed an isometric growth for S. ingentis and positive allometric for S. penicillata. Growth parameters and longevity values were moderate with an age at first maturity around one year for both species. The recruitment pattern showed continuous periods with peaks from May to October. Average natural mortality was 1.20 for S. ingentis and 1.29 for S. penicillata. Distribution and population dynamics information presented here for this two Rock shrimp species in the Gulf of California should be considered as base knowledge in subsequent studies on fisheries management.