The relationship between children's self-reported pre-procedure anxiety, fear and pain during BMA's and LP's and observed behavioral distress was examined in 41 pediatric oncology outpatients aged 3 to 15 years (29 male). The effects of demographic, child, and environmental variables, such as child's age, gender, ethnicity, parental pre-procedure anxiety, child's coping style, and the relationship between child's and parent's coping style, were also evaluated. Visual Analogue Scales (0-10) were used to quantify pre-procedure anxiety and children's self-reports of fear and pain during the procedure. The observed behavioral distress was determined by the sum score of the Procedure Behavior Checklist, which rates each of ten distress behaviors. Children's pre-procedure anxiety did not predict children's reported fear, pain, or behavioral distress during the procedures. Rather, children's age, ethnicity, and parental pre-procedure anxiety were found to be the main predicators of children's responses to medical procedures. Specifically, children's age was significantly inversely correlated with behavioral distress(r=-.35, p<.04). Children <7 years of age had a mean distress score of 47.8 (s.d. 11.0), versus children ≥7 years of age who had a mean of 40.2(s.d. 15.0). Ethnicity predicted children's pain ratings. Latino children reported significantly more pain than did Caucasian children (F(2)=3.40, p<.05): Latino mean=3.2 (s.d. 3.8); Caucasian mean=.48 (s.d..72). Greater parental pre-procedure anxiety was associated with greater child self reports of fear, regardless of children's own pre-procedure anxiety level (F(1)=5.5, p<.03); mean child fear ratings of children whose parents reported high pre-procedure anxiety =3.2 (s.d. 3.7), versus.67 mean (s.d. 1.3) for children whose parents reported low pre-procedure anxiety. The study's findings indicate that children's pre-procedure anxiety is not a major predicator of children's self-reports of fear and pain during BMA's and LP's or of their behavioral distress. Instead, children's age, ethnicity, and pre-procedure parental anxiety highly influence children's behavior and self-reported distress experiences during these procedures. Intervention should be targeted at these predicator variables.