Intraventricular (i.c.v.) administration of β-endorphin (β-END) has been shown to suppress lordosis behavior in ovariectomized (OVX) estrogen-progesterone (EP) primed rats, but the behavioral specificity of this effect is not known. Using OVX EP-primed rats, the present study assessed the effect of i.c.v. β-END on proceptive behavior as well as on lordosis (receptive) behavior, and attempted to discern whether the sexual effects were secondary to generalized nonspecific behavioral effects. Doses of 0.5–4 µg β-END (human) significantly suppressed lordosis behavior. Doses of 1 and 4 µg were used in experiments which measured proceptive behaviors (presentations and ear wiggling), and both doses abolished or nearly abolished the display of these behaviors. Administration of inactive peptide (a protein digest) had no effect on sexual behavior. Neither 1 nor 4 µg β-END elicited measurable catalepsy. In a series of tests for responsiveness to general somatosensory stimuli, 1 µg had no effect on responsiveness while 4 µg had minor effects, even though sexual activity was severely diminished after both doses. Blood pressure was unaltered by infusion of β-END (1 µg), although there was a significant reduction in heart rate. When open field behavior was tested in conjunction with sexual behavior, ambulation and rearing were significantly decreased after β-END treatment as compared with saline treatment. However, simple linear correlation tests showed a lack of correlation between the changes in open field behavior and the changes in sexual behavior, indicating that the effects of β-END on the two types of behavior may be unrelated. These results extend previous observations by more fully characterizing the effect of i.c.v. β-END on sexual behavior of the female rat. Although the sexual effects of β-END are not completely specific, the results indicate that the sexual suppression is not secondary to a generalized behav