This paper deals with research on acquisition of Spanish phonology by young children. The beginnings of this discipline are placed within the model of Generative Grammar, at the end of the 1960s. The two main areas of phonology are considered: on the one hand segments, and certain chronological sequences of segment acquisition, and on the other hand prosody, i.e. syllables, stress, intonation and rhythm. The most important issues of acquisition research are presented, including the relationship between perception and production, the role of prosody in acquisition, underlying representations, and the dependency of morphology on prosody. The main models of the field are also discussed, namely rules, parameters and constraints. The beginnings of morphological development and its dependence on phonology are briefly discussed as well. Finally, the acquisition of Spanish phonology in bilingual contexts is also described. The paper deals exclusively with normal first language acquisition, and does not refer to speech language impaired children nor to second language acquisition. ideas and claims about L1 phonological acquisition, and even about certain stages of acquisition, like the transition from babbling into language proper.The first pieces of work on L1 phonological acquisition were done on English. Stanford University, centered around the work of Charles Ferguson, was a flourishing center that grouped many phonologists who began to work on such issues, not limiting themselves to English, as Ingram worked on Italian, and Macken and Hochberg on Spanish, just to mention a few of the initial attempts to linguistically transcend English. Vihman started joint work with the CNRS in Paris, devoting efforts to several languages; a few phonologists, like Vogel and Vihman, began to pose questions related to bilingualism, i.e. the simultaneous acquisition of two languages (see Vihman 1985, Vogel 1975. Here, we will concentrate on work done on the acquisition of Spanish.Main issues of research were defined in work done on the acquisition of English. Two main themes can be identified: on the one hand, acquisition of English per se, in the sense of establishing a chronology for various landmarks. Obviously, young children produce words and utterances in ways that differ, some times substantially, from the language spoken by their parents and caretakers. Research should thus account for development: what resources do children have at the beginning, i.e. what is the initial state? And how and when do they arrive at the final state? Are there turning points in this evolution, or is it a continuous development towards the target? On the other hand, phonological theory proposes certain constructs that should be tested, and acquisition by the young human being is a test case from which theory can learn much. Among such constructs are notions like the phoneme, the syllable and all other constituents of the prosodic hierarchy, the underlying representations, and whether descriptions should be based on either rules or constraints.Resear...