This phytochemical study presents the isolation of eight alkaloids from Zephyranthes citrina Baker. The structures of the new alkaloids, zephycitrine (1) and 6-oxonarcissidine (2), were established by analysis of spectroscopic and spectrometric data. Processing the EtOH extract under acid-base conditions yielded the unreported isolation artifacts 3 and 4. This work also provides analytical data for alkaloids not properly described in the literature (5 and 6). The hippeastidine/zephyranine scaffolds in derivatives 3, 4, and 8-10 are also thoroughly discussed. Furthermore, a cytotoxicity screening of 25 Amaryllidaceae alkaloids isolated from Z. citrina was performed. Only the known alkaloids haemanthamine (12), haemanthidine (13), and lycorine (27) showed significant cell growth inhibition.