The factor structure and construct validity of a Spanish version of Spector, Carey, and Steinberg's Sexual Desire Inventory was examined with structural equation modelling and a nonclinical sample (N = 608). Confirmatory factor analysis indicated that Dyadic and Solitary sexual desire scales measured two factorially distinct constructs. Their internal consistency reliabilities were .87 and .88, respectively. Structural equation analysis indicated that both subscales are distinguishable from similarly conceptualized correlates of sexual desire: the Impersonal subscale of the Sex Fantasy Questionnaire and the Erotophilia measure of the Sexual Opinion Survey. However, the data raised some questions about an empirical distinction between dyadic sexual desire and intimate sexual fantasy.